WBBSE 9th Class Science Solutions Life Science & Environment Chapter – 1 Life and its Diversity

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West Bengal Board 9th Class Science Solutions Life Science & Environment Chapter – 1 Life and its Diversity

WBBSE 9th Class Life Science & Environment Solutions

TOPIC – 1

BASIC PROPERTIES OF LIFE

SUMMARY

Living organisms can perform reproduction, metabolism, locomotion and movement. They show sign of growth and respond towards stimuli. Thus they differ from non-living objects those do not have those abilities.
About 3.7 billion years back, the most primitive form of life emerged on earth from nonliving objects by chemical synthesis. Later various living organisms were evolved from that ancient life form.
According to Haldane and Oparin, life emerged on earth through the following steps-Origin of earth and transformation of primitive atmosphere (origin of earth, origin of simple inorganic compounds and gradual decrease in temperature of earth) or Chemosynthesis of life or chemogeny (origin of simple organic compounds, origin of complex organic compounds from. simple ones, origin of coacervate, origin of naked gene) → Organic evolution of life or biogeny (emergence of protocell, origin of prokaryotic cells, origin of autotrophy) → emergence of eukaryotic cells.
Haldane described the organic matter-rich hot water of the ancient ocean as ‘hot dilute soup. According to him, life emerged in this hot oceanic water of the primitive earth.
Various organic molecules in the ‘Hot dilute sour soup’ combined to form a colloidal matter, called coacervate. According to Haldane and Oparin, life emerged from coacervate-like colloids. Sidney Fox, on the other hand proposed that life originated on the earth from a cluster of organic molecules, called microsphere.
The variations of genes within organisms along with variety of species on earth denote biodiversity. Variations in organisms occur during gamete formation, mutations, etc. which ultimately cause biodiversity. Other than these, reproductive isolation and natural selection also lead to formation of biodiversity.

Long Answer Type Questions

1. Explain the basic properties of life.

Ans. Basic properties of life

From biological point of view, there are five basic properties of life. They are-

Reproduction: Reproduction is a biological process by which living organisms give birth to offsprings in their lifetime, in order to protect their races from being extinct.
Growth: Growth is the irreversible increase in dry mass and size of a living body. A living organism must exhibit growth and development in due course of time.
Metabolism: Metabolism is a set of life sustaining chemical reactions involving formation and breakdown of various nutrients within the body. Different metabolic activities like nutrition, respiration, excretion, etc. take place in a living organism.
Response to stimuli: Response to external and internal stimulus is an important character of a living organism. For example, if a moving millipede is touched, it coils around.
Adaptability: Adaptability is a property of life where any living organism tries to adjust itself, either structurally or behaviourally, according to the environmental changes.

2. Elucidate the process of origin of life on earth from inorganic matters.

Or, Write down the concept of Haldane and Oparin regarding origin of life.

Or, Briefly describe chemogeny of life. and Oparin regar

Ans. Origin of life on earth

In the famous book, titled ‘The origin of Life on Earth, Alexander Oparin expressed his view in this regard. John Haldane, a contemporary scientist, did support his view through a similar hypothesis, which was famous as ‘The theory of abiogenesis’ or the concept of biochemical emergence of life. According to them, life emerged on earth through three phases.

Origin of earth and transformation of primitive atmosphere: About 5 – 6 billion years back, the earth originated from a huge explosion, known as ‘Big Bang’ in the cosmos. At that time, the earth was a mass of burning gases, with temperature as high as 5000-6000°C. At that high temperature, it was difficult for the gases like Nitrogen, Hydrogen and Oxygen to exist independently in the atmosphere. They were rather present in the form of nitrides, hydrides, carbides and oxides of various metals or nonmetals. As a result, the atmosphere of the primitive earth was reducing in nature. Later moisture condensed in the sky to develop huge cloud followed by continuous rainfall that helped the earth to cool down gradually.
Chemosynthesis of life or chemogeny: Simple organic compounds were originated from inorganic matters. Scientists applied high electrical discharge or ultraviolet ray in the mixture of H₂, CH₄, CO, H₂O and got amino acids, simple carbohydrates and fatty acids. By means of polymerisation, simple organic compounds form complex and larger organic compounds. Such organic compounds are ultimately mixed in hot oceanic water to form the ‘hot dilute soup’ [As proposed by J Haldane]. The larger organic molecules in that hot dilute soup then clustered to form bubble-like colloidal matters, called coacervate [As per A. Oparin] or Microsphere. Gradually such objects were transformed into self-divisible protobionts [As per Sydney Fox].
Evolution of life or biogenesis or biopoesis: After comibing with neucleotides, coacervates can formed self-replicating protobionts or protocells. In course of time prokaryotes evolved from these protocells. Amongst these primitive cells the first emerged prokaryotes were chemoheterotrophs followed by chemoautotrophs. As soon as oxygen occurred in atmosphere, aerobic eukaryotes evolved from the anaerobic prokaryotes.

3. Represent the origin of life with the help of a flow chart.

Or, Schematically represent the path for the origin of life from non-living matters.

Ans. Flow chart showing the origin of life

4. What is biodiversity? Briefly discuss the sources of biodiversity.

Ans. Biodiversity

Biodiversity is the variability among living organisms at gene, species or ecosystem level, from all sources, including terrestrial, aquatic and any other ecological complex they belong to.

Sources of biodiversity

Variations from reproduction: Gametes unite during sexual reproduction. In this process mixing of genes occur, which results into diversity. On the other hand, gametes of an organism carry different combinations of genes. Union of two such gametes may lead to formation of different varieties of progeny.
Mutation: Genes control the characters of any organism. Sudden permanent alteration in DNA sequence may develop some new features in that particular organism. And this may give rise to progeny with different features.
Adaptation in changing environment: Climate and environment vary from place to place. The organisms; inhabiting there, adopt to that condition. In this process they develop certain features, which make them different form others. As we find additional respiratory organs in fishes of muddy water, long and thick fur of dogs in frozen southern continent.

Other than these, certain organisms become reproductively isolated due to geographical barrier or biological reasons. They develop typical endemic features. Sometimes due to natural selection, some organisms evolve as a new species.

5. Classify different levels of biodiversity.

Ans. Levels of biodiversity

Biodiversity has been classified into three levels-[1] Genetic diversity, [2] Species diversity and [3] Ecological diversity.

Genetic diversity: The various types of variations and combinations in the genetic composition among the individuals of a species is considered as genetic diversity. Due to genetic diversity, individuals of same species look and behave differently. Example-The diversity in the genes of different varieties of paddy, wheat, dogs, etc.
Species diversity: The diversity in number, richness and evenness in distribution of various species in a biotic community is regarded as species diversity. This is estimated by determining the number of variety of a species and the number of species inhabiting a specified area. Example-The diversity of species inhabiting the mangrove forest of Sundarban.
Ecological diversity: The variation of several ecosystems in a large geographical area is known as ecological diversity. The diversity of organisms from a microhabitat to a huge biome is included under ecological diversity. American ecologist Whittaker (1965), classified ecological diversity into three different sub-types. They are-
[A] α diversity: α diversity indicates the richness of species in a specific area or an ecosystem.

[B] β diversity: β diversity is the measure of comparative turnover of species in two different habitats of an ecosystem.

[C] γ diversity: γ diversity is the overall biodiversity of a large geographical realm, consisting of many typical habitats and ecosystems.

6. Describe the different types of variation along with their examples and significance.

Ans. Types of variation

Variation is broadly classified into two types-[1] Continuous variation and [2] Discontinuous variation.

Continuous variation: Any characteristic of a species that changes gradually over a range of values is considered to exhibit continuous variation. It is represented by a line graph. Example: Variation in human height, skin colour and weight.
Significance: Continuous variation creates diversity amongst the members of same species. The characteristic features which undergo natural selection are ultimately transferred to the next generation.
Discontinuous variation: Any characteristic of a species having only a limited number of possible values is considered to exhibit discontinuous variation. It is represented by a bar graph. Example: Variation in human blood group and human eye colour.
Significance: Mutation is the prime reason behind discontinuous variation. Mutation leads to the development of new species at a comparatively faster rate. Discontinuous variation leads to species diversity.

7. What are the important features of biodiversity?

Ans. Important features of biodiversity

[1] Comparatively high level of biodiversity has been noticed in tropical and subtropical region than temperate region. [2] Rate of biodiversity is very high in tropical rain forests in terrestrial ecosystem and coral reefs in aquatic ecosystem. [3] Insects are the diverse of all living organisms (56.4% of total species). [4] Reduction of genetic diversity of a species gradually leads to its extinction. [5] Biodiversity is not evenly distributed in all parts of the world.

Short Answer Type Questions

1. What is life?

Ans. Life is the condition that establishes the existence of a living organism on the basis of various characteristics such as growth, reproduction, metabolic activities, response to stimuli, adaptability, ageing, death, etc.

2. What are non-living objects?

Ans. Those objects which do not show any of the signs of life, such as growth, reproduction, metabolic activities, response to stimuli, ageing and senescence, etc., are called non-living objects.

3. Mention the similarity between living and non-living objects.

Ans. [1] Both living and non-living forms have size and shape. [2] Living and non-living matters are composed of different elements (like- C, H, O, N, S,P, etc.)

4. What is meant by reproduction? Why is it so important?

Ans. Reproduction is a biological process by which young individuals or offspring are produced from their matured parents.

Reproduction is a process by which any living form maintains its race in the living world.

5. What is meant by life cycle?

Ans. The cyclic course of events undergone by an organism, starting from its birth followed by growth, maturity, reproduction, ageing and finally death, is known as its life cycle.

6. What is meant by movement?

Ans. Movement is a characteristic phenomenon of any living organism by which it moves one or many parts of its body, spontaneously or in response to any stimulus, without any displacement.

7. What is meant by locomotion?

Ans. Locomotion is a characteristic phenomenon of any living organism, by which it changes its location spontaneously or in response to stimulus with the help of movement of its body part.

8. What is evolution?

Ans. Evolution is the slow, steady and continuous emergence of advanced and complex forms of life from primitive and simpler forms. It also involves change in heritable characters of biological population from one generation to the next.

9. What do you mean by excitability? Give an example.

Ans. Excitability: The ability of living organisms to react in response to a stimulus is called excitability.

Example: Leaflets of ‘touch me not’ plant (Mimosa pudica) droop when touched. This is an example of excitability.

10. Give an example of response to stimuli shown by plant.

Ans. The leaves of ‘touch me not’ (Mimosa pudica) plant droop when touched. This is an example of response to stimuli shown by a plant.

11. What is meant by senescence?

Ans. Senescence is the rocess of gradual and irreversible deterioration in the structural components of the body and decrease in the ability of a matured organism to deal with the stress of the environment.

12. What is meant by ageing? What is death?

Ans. Ageing: Ageing is the process of growing older with time, that is genetically determined and environmentally modulated.

Death: Death is the ultimate disappearance of all signs of life from a living organism.

13. What does the ‘chemogeny of life’ mean?

Ans. Chemogeny or chemosynthesis of life is the most modern concept, used to explain the biochemical origin of life on the earth. According to this concept, life originated naturally and spontaneously from simpler inorganic matters on earth, through various physical and chemical processes.

14. What is meant by biogeny? Mention the steps of this process?

Ans. Biogeny: The slow and gradual process of origin of life from simple organic compounds is called Biogeny.

Steps of Biogeny: Formation of coacervate or of Microsphere→Formation of naked gene→ Formation of protobiont or protocell→Origin of prokaryotes→Origin of eukaryotes.

15. Why was was atmosphere of primitive earth reducing?

Ans. During the origin of earth, its atmosphere was reducing in nature because- [1] Free oxygen was absent in air. [2] Due to very high temperature, gases like nitrogen, hydrogen, oxygen were present in a form of nitrides, hydrides and oxides of different metals and non-metals.

16. What is is meant by ‘hot dilute soup’?

Ans. According to the theory of chemosynthesis, before the emergence of life several organic molecules get mixed into the hot boiling water of the primitive ocean. Haldane denoted this hot broth of organic matter as ‘hot dilute soup!

17. What is coacervate?

Ans. Coacervates are minute (1-100µ) spherical, bubble-shaped, colloidal matters, composed of lipid, protein, carbohydrate and nucleic acid molecules, present in hot water of primitive ocean. Oparin first suggested this structure and named it as coacervate.

18. Mention the significance of coacervates in origin of life.

Ans. [1] coacervates accumulate solutes from medium and grow in size. [2] These are capable of synthesising larger organic molecules from smaller ones by polymerisation. That is why, Oparin suggested coacervates as precursor of living cells.

19. What is proteinoid? Mention its significance.

Ans. Proteinoid: Proteinoids are tiny clusters of closely attached amino acid molecules, which are formed in anaerobic condition at higher temperature.

Significance of Proteinoids: According to Sidney Fox, several proteinoids combined in hot water of primitive Ocean to form microspheres, which he denoted as precursor of protocells.

20. Mention the living features of microspheres.

Ans. [1] They are surrounded by a double-layered membrane, [2] They show osmotic activity, [3] Certain protein molecules present in the microspheres, have enzymatic activity, [4] Microspheres may divide through a process similar to binary fission.

21 Mention the significance of microspheres in origin of life.

Ans. [1] Microspheres can accumulate solute molecules from medium and grow in size. [2] It can utilise ATP. [3] Microspheres are selfreplicating. Due to these features Sidney Fox regarded it as precursor of life.

22. What are protobionts or protocells? Mention the significance of protocell.

Ans. Protobionts or protocells: In the primitive sea, nucleic acid molecules entered into protein coacervates to take the shape of primitive cells. These primitive structures are known as protocells.

Significance of protocell: First sign of life was noticed in protocells. These are regarded as precursors of living cells.

23. How did protocell originate?

Ans. Protocells were originated by natural insertion of RNA molecules within the coacervates or microspheres. The RNA molecules acted here as genetic material of these protocells, which enabled it to perform self-replication.

24. Mention two characteristic features of protocell.

Ans. [1] Protocells are the most primitive cell forms, which contain RNA as a genetic materiál.

[2] These are self-replicating forms, however, true reproductive features are absent in them.

25. What are naked genes?

Ans. According to the chemosynthetic theory, during the last phase of cell formation, purines, pyrimidines and pentose sugars united to form nucleic acids. These nucleic acid molecules were capable of self-replication. They were devoid of histone and other proteins and as they were not surrounded by nuclear membrane. They were called naked genes.

26. Mention characteristic features of naked genes.

Ans. [1] Naked genes are none other than RNA molecules, which are capable of self-replication. [2] Naked genes do not contain histone or other proteins.

Very Short Answer Type Questions

Multiple Choice Questions & Answers [MCQ]

1. Characteristic feature / features of life-

A. Metabolism

B. Excitability

C. Growth

D. All of these

Ans. D

2. One of the basic properties of a living organism is-

A. To intake oxygen

B. To move

C. To reproduce

D. To absorb water

Ans. C

3. Metabolism that increases dry weight of an organism-

A. Anabolism

B. Catabolism

C. Both A and B

D. None of these

Ans. A

4. Living organism is capable of acquiring and utilising energy. This typical feature of living organism is called-

A. Photosynthesis

B. Metabolism

C. Excretion

D. Excitability

Ans. B

5. Incapable of responding towards stimulus-

A. Plants

B. Animals

C. Bacteria

D. Rocks

Ans. D

6. Living forms differ from non-living objects due to its ability of-

A. Reproduction

B. Metabolism

C. Response to stimuli

D. All of these

Ans. D

7. Which of the followings is not a living feature?

A. Reproduction

B. Excitability

C. Adaptation

D. Decay

Ans. D

8. The feature of a living organism that may be seen or be created any non-living object is-

A. Respiration

B. Excretion

C. Excitability

D. Growth and movement

Ans. D

9. During boiling of cane sugar juice, sugar crystals gradually grow in size. Therefore, it is a-

A. Living body

B. Non-living object

C. Intermediate object between living and non-living

D. None of these

Ans. B

10. Which of the following is not a non-living feature?

A. Life cycle

B. Evolution

C. Excitability

D. None

Ans. D

11. All reactions of life take place within the-

A. Nucleus

B. Mitochondrion

C. Chromosome

D. Protoplasm

Ans. D

12. All the biochemical processes occurring within a living organism in order to sustain life, are collectively known as-

A. Energy

B. Metabolism

C. Nutrition

D. Digestion

Ans. B

13. Origin of earth took place-

A. 3.7 billion years back

B. 5 million years back

C. 4.7 billion years back

D. 6 million years back

Ans. C

14. Who established the concept of chemogenesis of life on earth experimentally?

A. Oparin and Haldane

B. Miller and Urey

C. Darwin

D. Fox

Ans. B

15. The concept of spontaneous generation of life was first proposed by-

A. Haldane and Oparin

B. Aristotle

C. Urey and Miller

D. Melvin Calvin

Ans. B

16. The concept of origin of life from inorganic matter is known as-

A. Special creation

B. Chemosynthesis

C. Biogenetic concept

D. Pangenesis

Ans. B

17. Who was the author of the famous book, titled ‘The origin of Life on Earth’?

A. Haldane

B. Oparin

C. Darwin

D. Sidney fox

Ans. B

18. Who did propose the concept of spontaneous creation of life on earth?

A. Arrhenius

B. Haldane

C. Oparin

D. Aristotle

Ans. D

19. The first step of chemical origin of life was the –

A. Origin of coacervates

B. Origin of complex organic compounds

C. Origin of simple organic compounds

D. Origin of proteinoids

Ans. C

20. The concept that proposes origin of life from inorganic matters is known as-

A. Origin of universe concept

B. Theory of spontaneous creation

C. Cosmozoic theory

D. Theory of Chemogeny

Ans. D

21 Temperature of earth during its origin was-

A. 2000-3 3000°C

B. 4000-5000°C

C. 5000-6000°C

D. 6000-7000°C.

Ans. C

22. Which gas was predominant in primitive atmosphere?

A. Nitrogen

B. Chlorine

C. Oxygen

D. Hydrogen

Ans. D

23. The essential gaseous ingredient of present atmosphere, which was absent in the primitive atmosphere before the origin of life, is-

A. Carbon dioxide

B. Nitrogen

C. Oxygen

D. Carbon monoxide

Ans. C

24. The concept of chemosynthesis of life on earth was proposed by-

A. Aristotle

B. Miller and Urey

C. Oparin and Haldane

D. Sidney Fox

Ans. C

Answer in a single word or sentence

1. Mention two common signs of life.

Ans. Respiration and nutrition

2. Name the biological process in which offspring are produced from parents?

Ans. Reproduction

3. What is excitability?

Ans. Excitability is a response of a living organism to any stimulus.

4. What is meant by response?

Ans. The reaction shown by a living organism towards any impulse, is called response.

5. Name the biological process that involves a combination biochemical reactions for sustaining life.

Ans. Metabolism

6. Name the life process that involves increase in mass and size of a living body.

Ans. Growth

7. Name the process that involves removal of metabolic wastes from the body.

Ans. Excretion

8. By which of the physiological processes does energy generate in living body?

Ans. Respiration

9. Millipedes coiled by touch. Which phenomenon does this behavior indicate?

Ans. Sensitivity or Excitability

10. Name the period from birth to death of an organism.

Ans. Life span

11. Which gases were present in primitive atmosphere of the earth?

Ans. NH₃, CH₄, H₂S, H₂O, HCN, H₂, etc.

12. What is chemogeny?

Ans. Chemogeny is the gradual process of synthesis of organic matters from inorganic compounds leading to the origin of life.

13. Mention two probable sources of energy required for chemogenesis of life.

Ans. Lightning and cosmic rays

14. Name the concept that states the origin of life from decaying matters.

Ans. Theory of spontaneous creation

15. What is the other name of the primordial soup?

Ans. Hot dilute soup

16. What is the importance of the ‘hot dilute soup’?

Ans. According to scientist Haldane, life was originated in the ‘hot dilute soup’ i.e., the organic matter-rich hot water of the primitive ocean.

17. What is the meaning of the term coacervate?

Ans. The term coacervate came from a Latin word, ‘coacervare’. It means cluster.

18. Who was the proponent of coacervate model?

Ans. Alexander Oparin

19. Sidney Fox in his experiment with amino acids could produce two products in sequence. Which are those?

Ans. Proteinoid and microsphere

20. Which type of matter proteinoid is?

Ans. Proteinoids are clusters of protein molecules, composed of amino acids.

21. Who did propose the microsphere model?

Ans. Sidney Fox

22. What is protobiont?

Ans. Membrane bound particle composed of nucleic acid and protein, which was the precursor of protocell, is called protobiont.

23. Mention two features of the primitive gene?

Ans. Primitive gene wass—[1] a RNA molecule and [2] it had no association with histone protein.

24. What was the nature of the first living organism on earth?

Ans. The first living organism on earth was an anaerobic chemoheterotroph.

25. Which type of nutrition did the first life on earth perform?

Ans. The first life on earth performed chemoheterotrophic nutrition.

26. Which is the main cause of species diversity?

Ans. Diversity of genes is the main cause of species diversity.

27. Mention one cause of biodiversity.

Ans. Mutation

28. Name the event of sudden, stable and inheritable change in gene?

Ans. Mutation

29. What is variation?

Ans. Any difference between two organisms can be called as variation.

Fill in the blanks

1. The first nucleic acid which originated on earth was ………

Ans. RNA

2. The country with the richest biodiversity on earth, is………

Ans. Brazil

3. The earliest photosynthetic living organism on this earth was ………

Ans. Cyanobacteria

4. The concept of spontaneous generation of life was rejected by ………

Ans. Pasteur

5. ……… and nucleic acid combined together to form life on primitive earth.

Ans. Protein

6. Proteinoid molecules conjugate to form……….

Ans. Microsphere

7. Human reproduction is an example of ……… reproduction.

Ans. Sexual

8. The primary basis of life is ………

Ans. Protoplasm

9. In catabolic metabolism, the dry weight of the body is ………

Ans. Decreases

10. In ……… matters no metabolic activity is found.

Ans. Non-living

11. If somebody pricks you with a pin, you will jump in pain. This is called………

Ans. Excitability

12 In primitive reducing atmosphere there was no ……… layer. So UV ray could reach the no earth easily.

Ans. Ozone

State True or False

1. Adaptability is the ability of a living organism to adjust with the changing environment.

Ans. True

2. Biogenesis is the synonym of biopoesis.

Ans. False

3. Scientist Haldane coined the term ‘primordial soup!

Ans. False

4. Hydrogen was the predominant gas in primitive atmosphere.

Ans. True

5. Mimosa pudica responds to stimulus.

Ans. True

6. A chalk is broken into two. It can be treated as reproduction.

Ans. False

TOPIC – 2

BIOLOGY AND ITS BRANCHES

SUMMARY

We study biology out of curiosity, to grow scientific outlook and to develop moral values.
Some of the branches of biology are Cytology, Molecular biology, Immunology, Genetics, Histology. Ethology, etc. Other than these, certain new branches of biology have also been developed, in combination with different branches of science. Such new branches of biology include Biophysics, Biochemistry, Biometry, Bioengineering, Bionics, Biotechnology, etc.
The science of biology has great impact on development of human civilisation. The modern approach of biology has helped in developing high-yielding and disease resistant varieties of crops and poultry birds. It has played immense role in modernising fishery, dairy farming, animal husbandry, brewery and all other food production and processing industries. Biology has also played a vital role in developing vaccines and medicines.
Biology has application in space science as well. Chlorella, a green alga, is used in space stations to maintain oxygen supply. Besides these, biology also helps to deal with several environmental issues, like pollution, acid rain, Ozone layer depletion, etc.

Long Answer Type Questions

1. Give a brief idea on different branches of classical biology.

Ans. Branches of classical biology

Different branches of classical biology are discussed below.

Morphology: This is the branch of classical biology, that deals with the study of size, shape and external features of living organisms.
Cytology: This branch of biology deals with the study of structure and function of cells.
Histology: This branch of biology deals with the study of structure, distribution and function of tissues in living organisms.
Anatomy: This branch of biology deals with the structures of different internal organs of plants and animals.
Physiology: This is the branch of classical biology, that involves the study of various metabolic reactions and the functional activities of life.
Genetics: This branch of biology deals with the study of heredity and variations of inherited features.
Evolutionary biology: This is the study of origin of life and gradual appearance of complexities in organisms.
Ethology: This branch of biology is concerned with the study of behaviour of organisms.
Ecology: This branch of classical biology deals with the study of interrelation between organisms and the environment.
Taxonomy: This is the oldest branch of classical biology that deals with the theoretical study of classification of living organisms including its basic principles and processes. It involves identification, nomenclature and classification of organisms.
Immunology: This branch of science deals with the study of immune system of our body and the reactions of antigens and antibodies occurring in our body.
Embryology: This branch of science deals with the structure and development of embryo of living organisms.
Pathology: This branch of science deals with the study of different diseases, their causes and preventive measures.
Paleontology: This branch of classical biology deals with the study of extinct organisms, through their fossils and thus, helps to know their geological history.

2. Give a brief idea on different branches of applied biology.

Ans. Branches of applied biology

Different branches of applied biology are discussed below.

Agriculture: This branch of applied biology deals with the practice of cultivation of crops and vegetables.
Horticulture: This is a branch of applied biology, which deals with the scientific practice of cultivation of flowers and fruits.
Forestry: This branch of applied biology deals with the methods, which help to reduce deforestation, such as afforestation and conservation of forest.
Pharmacognosy: This branch of science deals with the rearing and conservation of medicinal herbs and study of crude drugs and herbal medicines.
Sericulture: This branch of science deals with the scientific practice of rearing silkworm and extracting silk fibres from cocoons, for economic interest.
Pisciculture: This branch of applied biology deals with the scientific practice of breeding, rearing and capturing fishes for economic purpose.
Apiculture: This branch of science deals with the scientific practice of rearing honeybees in artificial hives and extracting honey from them.
Pearl culture: This is a branch of applied biology, that deals with the methods of rearing pearl oysters and extraction of pearl from them.
Lac culture: This branch of applied biology deals with the methods of rearing lac insects and extraction of shellac from them.
Poultry farming: This branch of applied biology deals with the breeding and rearing of poultry birds, for the production of eggs and meat.
Dairy farming: This branch of applied biology deals with the rearing of cattle for the production of milk.
Animal husbandry: This branch of applied biology deals with the practice of breeding of farm animals (cattle, pigs, horses, etc.) in order to develop their genetic qualities for human profit.
Plant breeding: This branch of applied biology deals with various methods for production of improved variety of plants.
Molecular biology: This branch of science deals with the study of different biomolecules and their activities within our body.
Biochemistry: This branch of science deals with the study of chemical processes occurring inside living organisms.
Microbiology: It is the study of microorganisms that are useful or harmful to man, plants and animals.

3. Mention the relationship of biology with other branches of science.

Ans. Relationship of biology with other branches of science

In course of time, biological science has developed further by sharing its concepts with other fields of science. This gave rise to some new and modern subjects within the domain of science. Some of these are discussed below.

Biophysics: This branch of science has been developed by the combination of biology and physics. It deals with the study and explanation of the critical structures of various organs and physical activities related to movement, locomotion, food capturing, etc., of living bodies, under the light of physics.
Biochemistry: This is a branch of science, developed by the combination of biology and chemistry. It deals with the study of nature of various chemicals, their classification and reaction processes occurring in the living organisms.
Biotechnology: This is a modern branch of science, developed for producing improved variety of plants or animals for human benefit, by means of genetic manipulation.
Biometry: This is a branch of science, developed by combination of biology and statistics. This subject helps to analyse different events and facts of biology, under the light of statistics.
Bionics: This branch of science has developed by the combination of biology and electronics. This is the study of mechanical systems which function like living organisms or parts of living organisms.
Biogeography: This branch of science has developed by the combination of biology and geography. It deals with the study of the distribution of flora and fauna in different geographical regions.
Anthropology: This branch of science has been developed for the study of humankind, under the light of geography, sociology and palaeontology.
Palaeontology: This branch of science is developed by the combination of biology and geology. It deals with the study of the fossils of primitive life forms.
Bioinformatics: This branch of science has been developed by the combination of biology and computer science. It deals with the analysis of complex biological data, especially genetic codes.
Astrobiology or exobiology: This is a modern branch of science, developed by the combination of biology and space science to study the effect of environment of outer space on living organism of earth.

4. Explain the applications of biology in various fields.

Ans. Applications of biology

Some important applications of biology are discussed below.

Development in agriculture: The ever-growing population of our country led to the problem of food scarcity, thereby increasing the demand for food. Application of biology has solved this problem to a great extent. Biology is applied at its best in the field of agriculture, to increase the productivity and quality of crops. Various fields of application of biology in agriculture are-
1. Production of high-yielding varieties of crops: By using the knowledge of genetics and applying the techniques of hybridization, high-yielding varieties of paddy, wheat, maize and several other crops have been successfully produced.
2. Production of seedless fruits: Concept of genetics and horticulture are combined to produce seedless varieties of fruits and to improve the productivity and size of fruits.
3. Pest control: Concept of biotechnology has been applied to develop certain pest resistant varieties of crops and vegetables. Several pests are now controlled biologically by using predators like ladybird beetles and parasites. Bacillus thuringiensis is a bacterium used to destroy pests.
4. Storing of crops and food: Inventions in the field of biology help us to protect and preserve crops and food for a longer period of time.
Fish production: Knowledge of biology has been applied in induced breeding technique and composite fish culture, to increase fish production and to meet the growing demand.
Poultry and dairy: Knowledge of biology has been used for the advancement of poultry and dairy farming techniques. By this process, the production of eggs, meat and milk has been increased.
Medicines and Medical equipments: Herbal medicines are used since ancient times. Study of biology has revealed several medicinally important plants and animal products, which are used for the benefit of human and animals. Knowledge of microbiology has helped to produce a number of antibiotics, such as, penicillin, streptomycin, neomycin, tetracycline, etc.

Medicines By the application of genetic engineering, human insulin or Humulin has been produced. Based on concepts of biology, different medical equipments like, CT scan, MRI, ECG machines have been devised. Biology plays an important role in forensic science as well.
Application of biology in space: Chlorella is the most photosynthetically efficient green alga. It is cultured in space stations, to maintain a continuous supply of oxygen and removal of carbon dioxide. Many microbes and other organisms are studied in space laboratories to know the effect of extreme conditions of space on life forms.
Industrial production: Industries like sericulture, lac culture, pearl culture reflect the role of biology in industrial production. The concepts of biology are utilised to increase the production of cosmetics, medicines, textile, paper, plastic, rubber, leather, wood, tea, coffee, bakery and brewery industries.
Controlling environmental pollution: Biological notions help us to control environmental pollution. Afforestation, social forestry and conservation of forest are some of the positive steps, undertaken globally for pollution control.
Population control: Population explosion is presently a burning problem for entire world. By applying different concepts of biology and medicine, scientists have invented different modern and effective birth contol techniques for controlling population.

Short Answer Type Questions

1. What is biology?

Ans. The branch of science that deals with the study, investigations, experiments, observations and discussions on the origin, development, structural features and physiological activities of different living organisms, is known as biology.

2. What do you mean by applied branches of blology? Give example:

Ans. Applied branches of biology: Applied branches of biology are those branches of biological science, in which, knowledge obtained from biology is applied for the welfare of human, animals and plants.

Example: Fishery, poultry, genetic engineering, etc.

3. What is zoology?

Ans. The branch of biological science that deals with the study of morphology, anatomy, physiology, taxonomy, geographical distribution and conservation of animals, is known as zoology.

4. What is botany?

Ans. The branch of biological science that deals with the study of morphology, anatomy, physiology, taxonomy, geographical distribution, medicinal uses and conservation of plants, is known as botany.

5. What is physiology?

Ans. The branch of biology that deals with the study of different activities and reactions related to various metabolic functions of living organisms, is called physiology.

6. What is anatomy?

Ans. The branch of biological science that deals with the structure and location of external and internal organs and organ systems of animals and plants, is known as Anatomy.

7. What is taxonomy?

Ans. Taxonomy is the oldest branch of biology, that deals with the identification, nomenclature and classification of living organisms on the basis of certain principles and processes.

8. What is biochemistry?

Ans. Biochemistry is a branch of science, developed by the combination of biology and chemistry, in order to study the nature of various chemicals, their classification and their reactions occurring in the living organisms.

9. What is microbiology?

Ans. Microbiology is a branch of biological science, that deals with the study of microorganisms like virus, bacteria and all other microscopic organisms, some of which are useful while others are harmful to humans, animals and plants.

10. What is biophysics?

Ans. Biophysics is an interdisciplinary branch of science, that is developed by the combination of biology and physics. It deals with the study and explaination of the critical structure of various organs and the physical activities related to movement and locomotion, food capturing, etc., of living bodies under the light of physics.

11. What is hygiene?

Ans. Hygiene is a discipline of science, related to biology and medicine that guides us to maintain personal cleanliness for protecting ourselves and the society against diseases so as to keep fit both physically and mentally.

12. What is genetics?

Ans. The branch of biology that deals with the laws and methods of transmission of hereditary characters from one generation to next is known as genetics.

13. What is evolutionary biology?

Ans. The branch of biological science that deals with the origin and evolution of different species on earth is known as evolutionary biology.

14. What is palaeontology?

Ans. Palaeontology is a combination of biology and geology that deals with the study of impressions or fossilised remains of ancient organisms in sedimentary rocks to get an idea about those organisms and their time.

15. What is biogeography?

Ans. The branch of biology that deals with the natural distribution of various organisms in different geographical regions, is known as biogeography.

16. What is molecular biology?

Ans. The branch of biology that deals with the study of molecular structures of different intracellular biomolecules, their functions and applications, is known as molecular biology.

17. What is immunology?

Ans. Immunology is a branch of biology, that deals with the study of structure and function of body’s immune system and the nature of reactions occuring within the body between different antigens and antibodies.

18. What is biometry?

Ans. Biometry is a combination of biology and statistics. It deals with collection, analysis, interpretation and organised presentation of data on various biological materials.

9. What is agriculture?

Ans. Agriculture is branch of applied biology that deals with method of cultivation, treatment of soil and plant diseases, development of high-yielding and disease resistant variety of seeds, storage and marketing of crops.

20. What is horticulture?

Ans. Horticulture is a branch of applied biology that deals with practice of cultivation and maintenance of flowers and fruits.

21. What is meant by animal husbandry?

Ans. Animal husbandry is the practice of breeding and rearing of domestic animals like cattle, pigs, poultry birds, etc., for the production of milk, meat and eggs.

22. What is bioinformatics?

Ans. Bioinformatics is a combination of biology and information science that deals with the collection, preservation and analysis of information on different biological materials, like-genes, DNA, RNA, polypeptides, etc.

23. What is astrobiology or exobiology?

Ans. Astrobiology or exobiology is a combination of biology and space science, which is concerned with the study of the effect of hostile environment of outer space on various life processes of terrestrial organisms and different biochemical reactions.

24. What are the objectives of studying exobiology?

Ans. The most important objective of studying exobiology is to find those organisms, that can withstand extreme conditions in space. Study of these organisms gives us an idea of those life forms, which came into being in extremely hostile environment of primitive earth. Study of this subject also gives us an idea of the reactions, which took place during abiogenesis of life on earth.

25. Mention the different branches of clinical biology.

Ans. The different branches of clinical biology areimmunology, serology, haematology, oncology, radiation biology, IVF (In vitro Fertilisation) biotechnology, veterinary science, etc.

26. What is serology?

Ans. Serology is the scientific study or diagnostic examination of blood and serum, especially with respect to the response of the immune system to pathogens or foreign substances.

27. What culture? meant by pearl culture? What is lac riculture?

Ans. Pearl culture: Pearl culture is a branch of applied biology that deals with the methods and techniques of rearing pearl oysters and extraction of pearl from them.

Lac culture: Lac culture is a branch of applied biology that deals with the methods of rearing lac insects and extraction of shellac (a resin secreted by the female lac insect) from them.

28. What is meant by bioenergetics? What is thanatology?

Ans. Bioenergetics: The branch of biology that deals with the transformation of energy required for the synthesis and breaking up of biomolecules, is known as bioenergetics.

Thanatology: Thanatology is the branch of science, that is concerned with the study of changes in a body after death and finding the cause of death.

29. What is bionics?

Ans. Bionics is a new branch of science developed by the combination of biology and electronics to study the mechanical systems that function like living organisms or part of living organisms.

30. What is gerontology?

Ans. Gerontology is a branch of science, that deals with ageing process. It is also known as geriatric studies. It mainly deals with the physical activities and problems faced during old age, senescence process of living cells, developing anti-oxidant medications, etc.

Very Short Answer Type Questions

Multiple Choice Questions & Answers [MCQ]

1. The branch of science that deals with the study of structures and life processes of living forms is called-

A. Psychology

B. Geology

C. Biology

D. Chemistry

Ans. C

2. Who did coin the term ‘Biology’?

A. Oparin

B. Lamarck

C. Aristotle

D. Linnaeus

Ans. B

3. The Greek word ‘Bios’ means-

A. Life

B. Organism

C. Organic

D. Microbes

Ans. A

4. Among the following, the oldest branch of biology is-

A. Cytology

B. Taxonomy

C. Histology

D. Ecology

Ans. B

5. The branch of biology that deals with the study of plants is called-

A. Botany

B. Zoology

C. Psychology

D. Anthropology

Ans. A

6. The branch of biology that deals with study of animals is called-

A. Botany

B. Zoology

C. Psychology

D. Physiology

Ans. B

7. Branch of biology related to microorganisms-

A. Microbiology

B. Embryology

C. Anatomy

D. Zoology

Ans. A

8. The branch of science dealing with biology of insects is-

A. Serpentology

B. Ecology

C. Entomology

D. Ornithology

Ans. C

9. The branch of biology that deals with study of birds is-

A. Ornithology

B. Ecology

C. Herpetology

D. Entomology

Ans. A

10. Which of the following contents are studied in cytology?

A. Body structure

B. Nutrition

C. Cell

D. Social behaviour

Ans. C

11. The branch of biology that deals with study of Fungi is called-

A. Phycology

B. Parasitology

C. Mycology

D. Microbiology

Ans. C

12. The study of ferns is called-

A. Bryology

B. Pteridology

C. Phycology

D. Mycology

Ans. B

13. The branch of biology that deals with different types of cells and tissues is called-

A. Cytology

B. Histology

C. Physiology

D. Psychology

Ans. B

14. The branch of biology that deals with the study of interactions between living organisms and the environment is-

A. Pathology

B. Ethology

C. Ecology

D. Embryology

Ans. C

15. The branch of science that deals with the study of different diseases and their causes is-

A. Ethology

B. Anatomy

C. Pathology

D. Physiology

Ans. C

Answer in a single word or sentence

1. What is the meaning of the word ‘biology’?

Ans. The Greek word ‘bios’ means life and logos’ means knowledge, therefore, ‘biology’ means the study of life.

2. Who is known as the ‘Father of Biology’?

Ans. Aristotle

3. Which are the two main branches of biology?

Ans. Two main branches of biology are— Classical biology and Applied biology.

4. Name one of the classical branches of biology.

Ans. Zoology

5. Name the branch of classical biology that deals with the relation of living organisms with environment.

Ans. Ecology

6. Name the branch of biology that deals with the study of immune system of the living body.

Ans. Immunology

7. Name an applied branch of biology.

Ans. Fishery

8. Name a combined branch of biology.

Ans. Biophysics [A combination of Biology and Physics]

9. Mention two modern branches of biology.

Ans. Bioinformatics and Bionics

10. In which branch of biology does concepts of biology combine with chemistry?

Ans. Biochemistry

11. Who is regarded as the ‘Father of Botany’?

Ans. Theophrastus

12. Who is regarded as the ‘Father of Zoology’?

Ans. Aristotle

13 Mention the relation between chemistry and biology?

Ans. To understand the different metabolic and physiological reactions studied in biology we need to study chemistry.

14. What is embryology?

Ans. Embryology is the study of structure and development of embryos.

15. What is cybernetics?

Ans. Cybernetics is the science that deals with the technique of communications and control systems in both machines and living organisms.

16. What do you mean by hybridisation?

Ans. Hybridisation is the process of crossing two genetically different individuals of same species to obtain offspring with desired set of characters.

17. Mention any three branches of applied biology.

Ans. Three branches of applied biology aresericulture, apiculture and animal husbandry.

18. What is apiculture?

Ans. Apiculture is the scientific practice of rearing honeybees in artificial hives and extracting honey from them.

19. What is sericulture?

Ans. Sericulture is the scientific practice of rearing silkworms and extracting silk fibres from cocoons for economic purpose.

20. What is pharmacy?

Ans. Pharmacy is the study of principles and practices of developing drugs for therapeutic use in humans, animals and plants.

21. What is silviculture?

Ans. Silviculture is the study of principles and practices of cultivation of trees for wood and use of timber and its byproducts.

22. What is entomology?

Ans. Entomology is the study of different insects which are useful and harmful to humans, animals and plants.

23. What is ethology?

Ans. The branch of animal biology that deals with the behavior of different animals, is known as ethology.

24. Name the science dealing with cancer.

Ans. Oncology

25. Which branch of science is developed by combination of biology and statistics?

Ans. Biometry

26. Mention one importance of hybridisation.

Ans. Through hybridisation we get progeny with superior quality.

27. Name a genetically modified plant.

Ans. Bt-brinjal

28. What are the things studied under Microbiology?

Ans. Microbes i.e., bacteria, virus, etc., are studied under microbiology.

29. Which branch of science deals with fossils?

Ans. Palaeontology

30. Name a few varities of cattle with higher yield of milk.

Ans. Sultani, Vagalpuri, Shahiwal are some Indian breeds of cows with very high yield of milk.

Fill in the blanks

1. Study of life and living organisms is known as ……….

Ans. Biology

2. The classical branch of biology that deals with study of algae is known as ……….

Ans. Phycology

3. Study of ………. is known as mycology.

Ans. Fungi

4. ………. deals with the study of crude drugs.

Ans. Pharmacognosy

5. Scientific study of production of flowers and ornamental plants is known as ……….

Ans. Floriculture

6. Palaeontology is the science that has developed by the combination of biology and ……….

Ans. Geology

7. The branch of science that deals with the study of origin and evolution of organisms is known as ……….

Ans. Evolutionary science

8. Study of blood and haemopoetic organs is known as ……….

Ans. Haematology

State True or False

1. Taxonomy is the oldest branch of biology.

Ans. True

2. Bioinformatics is the branch of science, which is a combination of biology and electronics.

Ans. False

3. Sericulture is a branch of applied biology.

Ans. True

4. Knowledge of microbiology is important for the production of antibiotics.

Ans. True

5. Knowledge of biology can be utilised to control population explosion.

Ans. True

6. Study of human behaviour is called thanatology.

Ans. False

7. The term ‘biology’ was coined by Lamarck.

Ans. True

TOPIC – 3

CLASSIFICATION OF DIVERSITY OF LIFE

SUB-TOPIC – 3.1

TAXONOMY

SUMMARY

Taxonomy is the process that involves identification, nomenclature and classification of various organisms based on their similarities and dissimilarities. Vast biodiversity in tropical region initiated development of modern taxonomy in Europe.
Swedish scientist Carolus Linnaeus was the first to explain scientific method of taxonomy in his famous books, ‘Systema Naturae’ and ‘Species Plantarum.
Identification, nomenclature and classification are the three main components of taxonomy. Scientific method of sorting out an organism by certain characteristic features is known as identification. Nomenclature is the scientific process of naming of a type of organism. Finally grouping of different types of organisms based on their similarities and dissimilarities is known as classification.
Carolus Linnaeus is regarded as the ‘Father of Taxonomy’.
The groups, in which all living organisms are placed, from gross similarities to subtle similarities, are called ranks or categories. Seven main categories are—Kingdom, Phylum, Class, Order, Family, Genus and Species.
The cluster of organisms placed in a specific rank, is regarded as taxon. For example, ‘Plantae’ is a taxon that comes under the category Kingdom. The arrangement of different taxa in higher to lower or lower to higher categories is known as taxonomic hierarchy.
Carolus Linnaeus introduced the method of binomial nomenclature of organisms. The first part of binomial name indicates the genus and the last one denoted the species. The generic name starts with a capital letter whereas, the species name comprises all small letters. Such names are printed in italics. In hand written scripts these two parts are to be underlined separately. Such binomial names are commonly known as scientific name of organisms.

Long Answer Type Questions

1. What is taxonomy? Write down the brief history of the development of taxonomy in pre-Linnaean period.

Ans. Taxonomy

The branch of classical biology that deals with practice and application of the laws of classification is known as taxonomy.

Pre-Linnaean development of taxonomy

Taxonomy is one of the oldest branches of biology, which has developed gradually since ancient time. The developmental phases of taxonomy, according to the ages, have been discussed here.

Ancient age: The concept of taxonomy has developed in India about 2500 years back. The glimpse of classification was noticed in Rig veda, Manusamhita and Agnipuran. Manu, an ancient sage, classified plants into oshadhi, banaspati, briksha, gulma, trina and balli. In ‘Briksha ayurveda, Rishi Parashar (1500 BC) classified plants on the basis of morphological features. Susruta, the famous ancient Indian medic, classified medicinal plants into 37 genera. Greek philosopher, Aristotle (384-322 BC) classified animal kingdom in two divisions-Anaima (having colourless blood) and Enaima (having red blood). Theophrastus (371-287 BC), the disciple of Aristotle, described 480 species of plants and classified those into trees, shrubs and herbs, in his famous book, ‘The Historia Plantarum’.
Roman age: Famous Roman naturalist Pliny the Elder (23-79 AD), classified plants in his book, ‘Naturalis Historia’ on the basis of their medicinal qualities. Roman physician Discordies, described about 600 medicinal plants in his famous book ‘The Materia Medica’.
Middle age: Italian botanist Caesalpino (1583), in his famous book ‘The Plantis, classified 1500 plants into trees, shrubs and herbs. In his classification, he put emphasis on the character of fruits and seeds. For this great work, Caesalpino is regarded as the pioneer of plant taxonomy. Gaspard Bauhin (1596) classified 6000 species of plants in his famous book ‘Pinax. He was the first person who tried to show the difference between genus and species. Famous scientist John Ray (1627-1705), classified plants based on the basis of the number of cotyledon of seeds in his book ‘Methodum Plantarum.

2. Briefly mention Linnaeus’s role in developing modern taxonomy. Name some taxonomists of post Linnaean period.

Ans. Linnaeus’s role in developing modern taxonomy

Modern taxonomy was set into light after the work of great Swedish scientist Carolus Linnaeus. He was the pioneer of scientific classification of plants and animals. In 1751, he first suggested the concept of binomial nomenclature in his famous book ‘Philosophia Botanica! Later in the year 1753, in his famous book ‘Species Plantarum, Linnaeus explained the process of binomial nomenclature. He studied numerous plants and animals, which he described in the latest edition of Bentham and Hooker his two famous books, ‘Species Plantarum’ (1753) and ‘Systema Naturae’ (1758), respectively.

Taxonomists of post-Linnaean period

Augustin de Candolle (1799), George Bentham (1862-1883), Joseph Dalton Hooker (1855), Adolph Engler, Karl Prantl (1887-1915), John Hutchinson (1926), Ernst Mayr (1963) are some of the renowned scientists who have enriched the taxonomic science to a great extent in the post-Linnaean period. In last twenty years, there was immense development noticed in the field of systematic classification of plant kingdom based on phylogenetic analysis. Takhtajan (1997), Cronquist (1981), etc. played promising role in this aspect.

3. What is binomial nomenclature? Mention the rules of binomial nomenclature.

Part Question, Mention two rules of binomial nomenclature.

Ans. Binomial nomenclature

Binomial nomenclature is the method of providing a scientific name to an organism. The name should contain two distinct epithets, the first one being genus and the second one is species. For example, Panthera tigris is the binomial nomenclature of tiger.

Rules of binomial nomenclature

The basic principles of binomial nomenclature was initially proposed by Linnaeus. Later in the 19th and 20th century, several international bodies of taxonomy, namely ICBN, ICZN, ICBaċN, ICVN and ICNCP, reviewed the prevailing rules and published the final edited version of the rules of binomial nomenclature. The most important rules are as follows-[1] Every organism must have a definite scientific name in Latin or Greek, comprising of two epithets-a generic name and a specific name. [2] Each of the epithets must not be composed of less than three or more than twelve roman alphabets. [3] The generic name is a noun, which should be written first, starting with a capital letter. [4] A generic name cannot be repeated in any other organism of the same or different kingdom. [5] Specific name should be written after generic name. It should be written in small letters. A specific name may be repeated under different genus. [6] The name of the discoverer may be mentioned in full or in abbreviation, after the specific name. [7] A scientific name should be printed in italics. If handwritten, each epithet should be separately underlined. For example, scientific name of mango tree should be written as Mangifera indica L. (Here L. stands for Linnaeus, the discoverer). [8] Any plant name, used before publication of ‘Species Plantarum’ (1753) and animal name, used before publication of 10th edition of ‘Systema Naturae’ (1758) must be discarded. [9] If a single organism is assigned two different names by two separate discoverers in different times, the former will be accepted and the latter will be discarded. This is known as Law of priority. [10] Detailed description with photograph of the sample used for nomenclature, must be published in any internationally accepted science journal. The type specimen, used for the nomenclature, must be preserved in any museum competent for such job.

4. What is meant by taxonomic hierarchy? How did Linnaean hierarchy modify in course of time?

Ans. Taxonomic heirarchy

Taxonomic hierarchy is the sequential arrangement of various categories or units of classification comprising of different taxa, from larger to smaller ranks. This includes seven categories.

Modification of Linnaean hierarchy

In course of time, newer variants of organisms have been discovered. Modern taxonomists faced problems in positioning those variants in the prevailing seven-step format. Consequently, Simpson (1961) suggested a 21-step hierarchy for animal classification. In this format, a new step ‘tribe’ was being inserted in between genus and sub-family. Besides this, some intermediate steps were also inserted in between the main steps prefixed with ‘supra, ‘sub’ and ‘infra! Later, ICBN proposed a 24-step hierarchy structure. Here, few more new steps were introduced, namely ‘section’ and ‘series’ between genus and species and ‘variety’, ‘form’ and ‘clone’ after species. However, the intermediate steps, prefixed with ‘supra’ and ‘infra’ are discarded. Thus, the old Linnaean hierarchy is modernised in course of time.

Short Answer Type Questions

1. How did the word ‘taxonomy’ originate?

Or, What is the etymology of the word ‘taxonomy’?

Ans. The word ‘taxonomy’ originated from two Greek words-‘taxis’ meaning ‘rank’ and ‘nomos, meaning ‘law’ or ‘custom. Therefore, the word ‘taxonomy’ literally means the ‘custom of ranking!

2. Who and in which year did coin the term “taxonomy’?

Ans. Famous botanist Augustin P de Candolle in the year 1813 did coin the term ‘taxonomy!

3. What are the three basic features of ree basic features of Linnaean taxonomy?

Ans. Three basic features of Linnaean taxonomy are-[1] Characterisation of living organisms based on certain observable features, [2] Naming the organisms according to binomial nomenclature and [3] Placing the individuals into seven major levels of hierarchical ranks.

4. Define characterisation.

Ans. Characterisation is an important feature of taxonomy which involves the process of listing the identifying features of collected specimen.

5. Mention the elements of discussion under taxonomy.

Or, Mention the main components of taxonomy.

Ans. The main elements of discussion under taxonomy are-[1] identification, [2] nomenclature, [3] classification and [4] documentation.

6. What is meant by identification?

Ans. Identification is a taxonomic process of separating out any organism from a cluster of other forms, on the basis of its distinctive features.

7. What does spot identification mean?

Ans. Spot identification is the process of separating out any plant or animal instantly from a cluster of other forms, on the basis of some external features.

8. What is meant by categorisation or grouping?

Ans. The taxonomic process by which any organism is placed under a taxon or rank, based on its similarities with the other members of that group, is called grouping or categorisation.

9. What is meant by nomenclature?

Ans. Nomenclature is a taxonomic process of providing a scientific name to a properly identified plant or animal, according to the internationally accepted rules in order to distinguish it from others.

10. What is classification?

Ans. Classification is a taxonomic process of placing or grouping organisms into proper taxonomic categories on the basis of similarities in characters.

11. What is meant by documentation?

Ans. Documentation is the scientific method of preservation of the type specimens, their description and all relevant data in museum or in laboratories, after the completion of taxonomic processes like identification, nomenclature and classification of a specimen.

12. Mention two problems of using common name of organisms with example.

Ans. Two problems of using common names are[1] Common names vary with regional languages, due to which an organism cannot be recognised universally. For example, crow is called ‘kak’ in bengali, ‘kawa’ in hindi, ‘corneille’ in french, ‘karasu’ in japanese etc. [2] Common name may create identity crisis. For example, silverfish is an insect, but the name apparently indicates a fish.

13. Mention importances or advantages of binomial nomenclature.

Ans. Importances of binomial nomenclature are[1] Binomial nomenclature is a globally accepted process. We can identify a species anywhere in the world by this name. [2] It nullifies the confusion created by different local names. [3] It is easy, meaningful and scientific. [4] In this process of nomenclature there is no chance of repetition.

14. What is law of priority in binomial nomenclature?

Or, What do you mean by the law of priority?

Ans. Law of priority is an important rule of binomial nomenclature. According to this rule any name that has already been published and accepted, cannot be used for naming other organism. According to this law any plant name introduced prior to publication of ‘Species Plantarum’ before 1 May, 1753 and any animal name published prior to publication of 10th edition of ‘Systema Naturae’ before 1 August, 1758 are not accepted.

15. What is trinomial nomenclature?

Ans. Trinomial nomenclature is the method of providing a scientific name to an organism where the name should contain three distinct epithets, genus, species and subspecies. For example, Homo sapiens sapiens is the trinomial nomenclature of human.

16. Why are scientific names written in Latin?

Ans. Latin is an old and dead language, hence it will not undergo any change with time. That is why, scientific names are written in Latin to keep the names unchanged for ever.

17. Which are the two parts of a scientific name?

Ans. A scientific name comprises two parts. The first part is genus and the second part is species. For example, scientific name of man is Homo (genus) sapiens (species).

18. Scientific name of Amoeba is Amoeba proteus. In this name which portion does Indicate the genus and which one the species?

Ans. In the name Amoeba proteus, Amoeba indicates its genus and proteus indicates the species.

19. What does Homo sapiens Linn., 1785 mean?

Ans. Homo sapiens Linn., 1785 gives us a few informations, like-[1] Homo sapiens indicate the scientific name of human, [2] The first portion indicates the genus and the second part is the species, [3] Here Linn. indicates a portion of the name of the propounder, i.e., Linnaeus and [4] 1785 indicates the year of propounding of the scientific name.

20. Mention the importances of classification.

Ans. The importances of classification are as follows-[1] By means of classification, an organism can be sorted out easily and quickly from a cluster of organisms. [2] Classification helps to determine the interrelationship among different groups of organisms.

21. What is ICBN? Mention its role.

Ans. ICBN: ICBN or International Code of Botanical Nomenclature is the sole international organisation to formulate and modify the rules of scientific naming of plants.

Role: ICBN provides guidance for correct placement of each taxon and method of nomenclature of the plants.

22. What is ICZN? Mention its role.

Ans. ICZN: ICZN or International Code of Zoological Nomenclature is the sole international organisation to formulate and modify the rules of scientific naming of animals.

Role: ICZN provides guidance for correct placement of each taxon and method of nomenclature of the animals.

23. What is hierarchy?

Ans. Hierarchy is the sequential arrangement of various categories of classification comprising different taxa from larger to smaller or smaller to larger ranks.

24. What are taxonomic categories?

Ans. Taxonomic categories are the units in which plants or animals are grouped during classification. Species, genus, family, order, class, phylum, etc. are the examples of different taxonomic categories.

25. What is taxon?

Ans. Taxon is the basic unit of hierarchy, which is a rank, given to a group of organisms with similar features, during classification.

Very Short Answer Type Questions

Multiple Choice Questions & Answers [MCQ]

1. Who is known as the ‘Father of Zoology’?

A. Aristotle

B. Theophrastus

C. Hippocrates

D. John Ray

Ans. A

2. Plant morphology was first described by-

A. Aristotle

B. Pluto

C. John Ray

D. Theophrastus

Ans. D

3. The Word ‘Systematics’ is coined by-

A. Lamarck

B. Linnaeus

C. Aristotle

D. John Ray

Ans. B

4. Taxonomy of organisms involves their-

A. Identification, nomenclature and classification

B. Collection and identification

C. Preservation

D. None of these

Ans. A

5. The method of categorisation of closely related organisms is-

A. Nomenclature

C. Classification

C. Identification

D. Hierarchy

Ans. B

6. Systematics is-

A. Nomenclature

B. Identification

C. Classification

D. All of these

Ans. D

7. Binomial nomenclature is-

A. A scientific name comprising of a generic and a specific epithet

B. A Latin name

C. Scientific name given to a plant

D. One name given by two different scientists

Ans. A

8. Method of binomial nomenclature was first explained in the book-

A. Systema Naturae

B. Genera Plantarum

C. Species Plantarum

D. The Plants

Ans. C

9. Propounder of ‘Binomial nomenclature’ is-

A. Aristotle

B. Linnaeus

C. John Ray

D. Lamarck

Ans. B

10. Each unit of the accepted method of classification of organisms is known as-

A. Species

B. Variety

C. Genus

D. Taxon

Ans. D

11. Hierarchy system in classification was introduced by-

A. Mayrs

B. Linnaeus

C. Simpson

D Hutchinson

Ans. B

12. Number of taxa in taxonomic hierarchy is-

A. 27

B. 7

C. 17

D. 9

Ans. B

Answer in a single word or sentence

1. Name the branch of biology that deals with identification, classification and nomenclature of organisms.

Ans. Taxonomy

2. Name the book by Theophrastus, in which classification of plants were discussed?

Ans. Historia Plantarum

3. Name an aquatic animal having same common name and generic name.

Ans. Octopus

4. Give an example of a fish having same generic and specific name.

Ans. Catla catla

5. Name a terrestrial animal, having same common and scientific name.

Ans. Gorilla gorilla

6. Which type of organisms are mostly known by their scientific names?

Ans. Most of the protozoa are known by their scientific names, such as Amoeba, Paramoecium, etc.

7. Which is the specific unit of classification?

Ans. Taxon

8. Name the systematic framework of classification with fixed number of rank.

Ans. Hierarchy

9. In his famous book in Latin, Linnaeus classified several animals and plants. Which book is it?

Ans. Systema Naturae

10. Which is the main book of classification by Carolus Linnaeus?

Ans. Systema Naturae [1758]

11. In which book did Linnaeus mentioned the concept of binomial nomenclature?

Ans. Philosophia Botanica [1751]

12. Mention the year, prior to which the published scientific names of animals are not accepted.

Ans. 1758, the year of publication of the 10th edition of ‘Systema Naturae.

13. The scientific names of animals, published before which year, were considered invalid?

Ans. 1758

14. The binomial nomenclature of animals, accepted by ICZN, was published in which edition of Systema Naturae’?

Ans. 10th edition

15. Which year’s edition of ‘Species Plantarum’ was accepted by ICBN for binomial nomenclature of plants?

Ans. 1753

16. Name the scientist who gave the modern definition of species.

Ans. Ernst Mayr (1966)

17. Which is the primary unit of classification?

Ans. Species

18. What is the scientific name of India’s national fruit?

Ans. Mangifera indica (Mango)

Fill in the blanks

1. The theoretical study of classification is known as ……….

Ans. Taxonomy

2. The term alpha taxonomy was first used by ……….

Ans. Willium Turrill

3. In the year 1968, the word beta taxonomy was first used by ……….

Ans. Ernst Mayr

4. ………. is known as the ‘Father of botany.

Ans. Theophrastus

5. The term ‘species’ was coined by ……….

Ans. Carolus Linnaeus

6. Scientist ………. was the pioneer to define the species.

Ans. John Ray

7. The concept of ‘binomial nomenclature’ was proposed by ……….

Ans. Linnaeus

8. Carolus Linnaeus was a citizen of ……….

Ans. Sweden

9. A family comprises of related ……….

Ans. Genera

State True or False

1. While printing a scientific name it is necessary to underline each word separately.

Ans. False

2. The name of the propounder of any scientific name should be mentioned at its end.

Ans. True

3. A few kingdoms unite to form a phylum.

Ans. False

4. The category, ‘Division’ is used during classification of plants.

Ans. True

5. Order is a category in Linnaean hierarchy.

Ans. True

6. The functional unit of classification is species.

Ans. True

7. Genus is a category and sapiens is a taxon.

Ans. True

8. Human belongs to kingdom Animalia.

Ans. True

SUB-TOPIC – 3.2

FIVE KINGDOMS OF LIFE

SUMMARY

In the year 1969, Robert Herding Whittaker arranged all the organisms on earth into five different Kingdoms. These are-Monera, Protista, Fungi, Plantae and Animalia. The main criteria of the five kingdom classification were cellular structure, body organisation, mode of nutrition, ecological role and phylogenetic relationships.
Kingdom Monera includes all unicellular, prokaryotic organisms, like bacteria, cyanobacteria or blue-green algae, etc.
Kingdom Protista comprises all unicellular, eukaryotic microorganisms. This kingdom includes all species of protozoa (example—Amoeba sp., Paramoecium sp., etc.).
Kingdom Fungi comprises all types of fungi on earth. The members of this kingdom are eukaryotic and heterotrophic. Yeast, mushroom, etc. belong to this group.
All types of plants belong to kingdom Plantae. These are eukaryotic and autotrophic organisms. Example-grass, mango tree, etc.
All the animals on earth are included in kingdom Animalia. These are eukaryotic, heterotrophic and multicellular organisms. Example-fish, human, etc.

Long Answer Type Questions

1. Explain the basis of five kingdom classification.

Ans. Basis of five kingdom classification

The characteristic features, based on which Whittaker proposed his five kingdom classification, are discussed below.

Complexity of cellular structure: On the basis of this feature, the living world is divided into two main divisions-
1. Prokaryotes: Primitive forms without true nucleus.
2. Eukaryotes: More complex forms alongwith true nucleus and membrane-bound cell organelles.
Complexity of body structure: Based on the number of cells present in a living body, organisms are classified into two groups-
1. Unicellular: Body is made up of single cell.
2. Multicellular: Body is made up of many cells. In case of multicellular forms, the nature of tissue and tissue systems are also taken into consideration.
Mode of nutrition: Living forms are classified into two main types, on the basis of their modes of nutrition. These are-
1. Autotrophs: They are photosynthetic forms, capable of preparing their own food.
2. Heterotrophs: These are organisms which depend directly or indirectly on autotrophs for food.
Role in ecosystem: Based on their roles in ecosystem, living forms are classified into three types-
1. Producers: They synthesise their own food within their body. Mainly photosynthetic green plants belong to this group.
2. Consumers: They depend directly or indirectly on producers for food. These include all animals.
3. Decomposers: They take part in biodegradation of organic matters. Various bacteria and fungi belong to this group.
Phylogenetic relation: Besides morphological, anatomical, biochemical and genetic features, the evolutionary trend of different groups are equally emphasised in this type of classification.

2. Mention any three identifying features of kingdom Monera. Give two examples of organisms tures of kingdom Ment belonging to kingdom Monera.

Part Question, Mention any two characteristic features of kingdom Monera.

Ans. Identifying features of kingdom Monera

Three identifying features of kingdom Monera are as follows-

Cell and cellular organisation: Members of this kingdom are unicellular and microscopic. Their cells lack any membrane-bound organelle, as well as true nucleus (i.e. prokaryotic cells). Their genetic material is naked circular DNA. Ribosomes and chromatophores are present. The major structural component of cell wall is peptidoglycan.
Mode of nutrition: They can have heterotrophic (i.e. parasitic, saprophytic, symbiotic, commensalistic and mutualistic) or autotrophic modes of nutrition. Autotrophs are either photosynthetic or chemosynthetic.
Role in ecosystem: Photosynthetic and chemosynthetic forms play the role of producers. Heterotrophs act as consumers and saprophytes act as decomposers.

Two examples of organisms belonging to kingdom Monera Two examples of organisms belonging to kingdom Monera are Mycobacterium tuberculosis and Escherichia coli.

3. Mention any three identifying features of kingdom Protista. Give two examples of organisms belonging to kingdom Protista.

Part Question, Mention two main features of Protista.

Ans. Identifying features of kingdom Protista

Three identifying features of kingdom Protista are as follows-

Cell and cellular organisation: These are unicellular, microscopic organisms (exception-kelps are multicellular and can be seen with naked eyes). Cells contain membrane-bound cell organelles and true nucleus (i.e. eukaryotic cells).
Mode of nutrition: Their modes of nutrition can be heterotrophic (parasitic, symbiotic) or autotrophic.
Role in ecosystem: Photosynthetic organisms (autotrophs) play the role of producers and heterotrophs act as consumers.

Two examples of organisms belonging to kingdom Protista

Two examples of organisms belonging to kingdom Protista are Amoeba proteus and Euglena viridis.

Short Answer Type Questions

1. What is two kingdom classification?

Ans. In 1758, Carolus Linnaeus proposed the concept of two kingdom classification. He divided all organisms on earth into two kingdoms. Those were-[1] Kingdom Plantae- It includes all the plants and [2] Kingdom Animalia- It includes all the animals.

2. Mention the disadvantages of two kingdom classification.

Ans. The disadvantages of two kingdom classification are-[1] Fungi are treated as plants, though they are incapable of photosynthesis. [2]Prokaryotic bacteria are included into plant group.

3. Mention the basic criteria of five kingdom classification proposed by Whittaker.

Ans. Basic criteria of five kingdom classification proposed by Whittaker, are-[1] Structural complexities of cells, [2] Morphology of organisms and cellular association, [3] Mode of nutrition and reproduction, [4] Ecological role and [5] Phylogenetic relationship.

4. Name the five kingdoms of the living world, as proposed by Whittaker.

Ans. The five kingdoms of the living world, as proposed by Whittaker are-Monera, Protista, Fungi, Plantae and Animalia.

5. What is meant by eukaryotic cells?

Ans. The cells, which possess well-organized nucleus and membrane-bound cell organelles, are known as eukaryotic cells. Example-cells of all higher plants and animals.

6. According to five kingdom classification, which organisms are included in kingdom Monera?

Ans. According to five kingdom classification, prokaryotic, unicellular organisms, such as, Cyanobacteria, Rickettsia, Spirochaetes, Mycoplasma and all other bacteria are included in kingdom Monera.

7. What is meant by prokaryotic cells?

Ans. The cells, which do not possess true nucleus and membrane-bound cell organelles, are called prokaryotic cells. Example-bacteria (Escherichia coli), blue-green algae (Anabaena circinalis) etc.

8. What is meant by Protista?

Ans. The word Protista has been derived from a Greek word ‘Protiston’, which means ‘first of all Ernst Haeckel coined the term, “Protista”. It is a kingdom of the living world, which is comprised of eukaryotic, mostly unicellular, microscopic organisms. Example-Amoeba proteus, Euglena viridis etc.(exception-kelp is a multicellular protist).

9. What is meant by protozoa? Give example.

Ans. The term protozoa indicates a group of organisms that are microscopic, unicellular eukaryots, belonging to kingdom Protista. Example: Amoeba sp., Paramoecium sp. etc.

Very Short Answer Type Questions

Multiple Choice Questions & Answers [MCQ]

1. Five kingdom classification was introduced in the year

A. 1959

B. 1869

C. 1969

D. 1896

Ans. C

2. Whittaker divided the living world into

A. Five Phyla

B. Five Classes

C. Five Kingdoms

D. Five States

Ans. C

3. The kingdom that comprises the oldest and the simplest group of organisms is kingdom

A. Monera

B. Protista

C. Fungi

D. Plantae

Ans. A

4. Which kingdom has all prokaryotic members?

A. Kingdom Protista

B. Kingdom Fungi

C. Kingdom Monera

D. KingdomAnimalia

Ans. C

5. Nuclear membrane and nucleolus is absent in

A. Kingdom Monera

B. Kingdom Protista

C. Kingdom Plantae

D. None of these

Ans. A

6. In which of the following groups, DNA is not associated with protein?

A. Kingdom Monera

B. Kingdom Protista

C. Kingdom Plantae

D. Kingdom Animalia

Ans. A

7. Out of the five kingdoms, proposed by Whittaker, Archebacteria, Eubacteria and Cyanobacteria belong to kingdom

A. Monera

B. Protista

C. Fungi

D. Plantae

Ans. A

8. In which kingdom does slime mold belong to?

A. Monera

B. Protista

C. Fungi

D. Plantae

Ans. B

9. Out of the five kingdoms, proposed by Whittaker, in which kingdom does diatoms and dinoflagellates belong to?

A. Monera

B. Protista

C. Fungi

D. Plantae

Ans. B

10. An organism is unicellular, eukaryotic and non-chlorophyllus. In which of the five kingdoms may it be placed?

A. Monera

B. Protista

C. Fungi

D. Protista or Fungi

Ans. D

Answer in a single word or sentence

1. Which type of cells are found among the members of kingdom Monera?

Ans. Prokaryotic cells

2. What are the major cell wall components of the members of kingdom Monera?

Ans. Polysaccharides and amino acids

3. In which kingdom do blue-green algae belong to?

Ans. Kingdom Monera

4. Write down the scientific name of two cyanobacteria.

Ans. Anabaena circinalis, Nostoc commune

5. Write down the name of a photosynthetic Monera.

Ans. Anabaena

6. Which is the smallest member of kingdom Monera?

Ans. Mycoplasma gallicepticum

7. What is the main structural component of the cell wall of Escherichia coli?

Ans. Peptidoglycan

8. Which kingdom lacks true nucleus?

Ans. Kingdom Monera

9. Which kingdom comprises unicellular eukaryotic organisms?

Ans. Kingdom Protista

10. Members of which kingdom perform the role of producers, consumers as well as decomposers in any ecosystem?

Ans. Kingdom Protista

11. Which members of kingdom Protista typically possess two flagella?

Ans. Dinoflagellates

Fill in the blanks

1. The concept of two kingdom classification was introduced in the year ………

Ans. 1758

2. The five kingdom classification of living world was proposed by scientist ……..

Ans. Whittaker

3. Prokaryotic cells belong to kingdom ……..

Ans. Monera

4. Mycoplasma is placed under the kingdom ……….

Ans. Monera

5. Nostoc is a cyanobacteria, which belongs to kingdom ……….

Ans. Monera

6 Bacterial cell is …….. in nature.

Ans. Prokaryotic

7. Unicellular eukaryotic animals are included under kingdom ……….

Ans. Protista

8. Euglena has been placed under kingdom ……….. according to five kingdom classification.

Ans. Protista

9. Amoeba belongs to kingdom …………

Ans. Protista

SUB-TOPIC – 3.3

CLASSIFICATION OF KINGDOM PLANTAE

SUMMARY

The plants on earth are primarily classified into two main types-(i) Cryptogamae or the plants and or the flowering plants.
Cryptogams of the non-flowering plants are of three types Algae, Bryophyta and Pteridophyta. Phanerogams or the flowering plants, on the other hand, are of two types, viz.-Gymnospermae and Angiospermae. The Angiosperms are also of two types(i) Monocotyledonae and (ii) Dicotyledonae.
Vegetative plant body of algae cannot be differentiated into root, stem and leaf. Hence, their body is thallus-like and they are called thallophytes. These are aquatic cryptogams. They may be unicellular (e.g-Chlamydomonas sp.), colonial or multicellular (e.g.-Volvox sp.[spherical] and Spirogyra sp.[ribbon-shaped]).
Bryophytes are the first group of terrestrial plants. Usually, they grow in moist land but they need, at least, a thin film of water for fertilisation. Therefore, bryophytes are called ‘the amphibians of plant kingdom: Some bryophytes are thallophytic which are called liverworts (eg-Riccia sp.), whereas, some others bear root, stem and leaf-like structures called rhizoids, caulids and phyllids respectively. This type of bryophytes are commonly known as moss(e.g.-Pogonatum sp.).
Pteridophytes are the first true land plants commonly known as ‘ferns. These plants show true body differentiation into root, stem and leaf systems. Roots, stems and leaves are traversed by primitive type of vascular or conducting ie, tissues. Hence, pteridophytes are also known as ‘vascular cryptogams’ (e.g.—Dryopteris sp.).
Gymnosperms are the seed-bearing flowering plants. These plants bear naked seeds because of the absence of ovary or fruit (e.g.-Pinus sp., Cycas sp.)
Angiosperms are the largest group of plants which bear seeds those are protected in a specialised structure called fruits. Angiospermic plants are classified into two major types. One type of plants contains seeds with single cotyledon, called monocotyledonous plants (eg-paddy, wheat, etc). The other type of plants has seeds with two cotyledons, hence are known as dicotyledonous plants (e.g.-sweet pea, mango, etc.).

Long Answer Type Questions

1. Mention the main characteristic features of algae. Give two examples.

Ans. Characteristic features of algae

[1] Algae are unicellular or multicellular aquatic thallophytes. [2] These are autotrophic, i.e., they can synthesise their own food within the body, due to the presence of chlorophyll. [3] Algal cell wall is mainly composed of cellulose and pectin. [4] Algal cells have variously shaped chloroplasts, which contain photosynthetic pigments and stored food like starch. [5] Chloroplasts contain one or more colourless protein bodies are known as pyrenoids. Pyrenoids are ensheathed by starch grains. [6] Algae reproduce vegetatively, asexually and sexually.

Examples of algae

Two examples of algae are Spirogyra maxima and Volvox globator.

2. Mention the main characteristic features of bryophytes. Give two examples.

Ans. Characteristic features of bryophytes

[1] Bryophytes are green, photosynthetic and non-vascular plants. [2] Plants are either thallus-like or have indistinguishable stem-like caulid, leaf-like phyllid and rhizoids in place of roots. [3] The plant body of bryophytes is gametophytic. [4] Sporophyte depends upon the gametophyte for survival. [5] Both male and female reproductive organs are multicellular. [6] Alternation of generations is distinct and unequal, where gametophytic generation dominates over the sporophytic generation.

Examples of bryophytes

Two examples of bryophytes are Riccia fluitans and Funaria hygrometrica.

3. Mention the main characteristic features of pteridophytes. Give two examples

Or, Mention three characteristic features of vascular cryptograms. Give example.

Ans. Characteristic features of pteridophytes

[1] Pteridophytes are multicellular, non-flowering plants with vascular tissue system. [2] Vascular system is composed of xylem and phloem. [3] Vegetative body is differentiated into roots, stems and leaves. [4] The independent plant body is sporophytic. [5] Sporophylls or spore-bearing leaves either arrange themselves to form cones or remain free as compound leaves. [6] Alternation of generations is distinct and unequal, where sporophytic generation dominates over the gametophytic generation.

Examples of pteridophytes

Two examples of pteridophytes are Dryopteris filix-mas and Marsilea minuta.

4. Mention the main characteristic features of gymnosperms. Give two examples.

Ans. Characteristic features of gymnosperms

[1] Gymnosperms are perennial sporophytic trees. [2] Vegetative body is differentiated into roots, stems and leaves. [3] Leaves are of two types-dry, brown scale leaves and green foliage leaves. Foliage leaves are either simple, needle-like or compound. [4] Vascular system present but xylem and phloem are devoid of trachea and companion cells respectively. [5] Fruits absent, that is why seeds remain naked. [6] Seeds bear more than one embryo, a feature typically known as polyembryony. [7] In gymnosperms, endosperm develops before fertilisation.

Examples of gymnosperms

Two examples of gymnosperms are Pinus roxburghii and Gnetum ula.

5. Mention the main characteristic features of angiosperms. Give two examples.

Ans. Characteristic features of angiosperms

[1]Angiosperms are either herbs, shrubs or trees. [2] Their life span varies from annual, biennial to perennial. [3] Vascular tissue system is highly developed. Xylem and phloem are composed of all the components. [4] Flower develop ovary, which matures into fruit. Seeds remain protected inside the fruit. [5] Seeds may have one or two cotyledons. [6] In angiosperms, endosperm develops after fertilisation.

Examples of angiosperms

Two examples of angiosperms are Cocos nucifera and Mangifera indica.

Short Answer Type Questions

1. What is meant by thallus? Give example.

Ans. Thallus: The plant body that is indivisible into root, stem and leaves is called thallus.

Example: Almost all algae and some bryophytes, like Riccia, has thallus-like body.

2. What is thallophyta?

Ans. Thallophyta is a plant group, that includes those plants having flat thallus-like bodies, which are not divisible into root, stem and leaf. Example-Algae.

3. What is meant by algae?

Ans. The simplest form of autotrophic, aquatic plants, with thallophytic vegetative body, made up of mainly eukaryotic cells, without any tissue differentiation and having unicellular sex organs, are called algae. Example-Spirogyra sp., Chara sp.

4. What are bryophytes?

Ans. Bryophytes are simple, non-flowering plants with dominant gametophytic generation, devoid of true roots, stems, leaves and vascular tissues systems, grow in moist soil but need water for fertilisation. Example-Pogonatum sp., Sphagnum sp. Pogonatum sp.

5. What are rhizoids?

Ans. Rhizoids are branched, colourless, very fine thread-like structures growing from the base of the gametophores or the ventral side of the thallus of bryophytes and help to absorb water and minerals from soil and affix the plant with the subtratum.

6. What are caulids and phyllids?

Ans. Caulid: The stem-like structures of the gametophores of bryophytes are called caulid. Phyllid: The leaf-like structures. of the gametophores of bryophytes are called phyllid.

7. How do bryophytes grow everywhere?

Ans. Bryophytes have root-like rhizoids instead of proper root system. These rhizoids are efficient enough to absorb moisture from any type of surfaces, even from rocky surface from where plant root can’t absorb water. Therefore, bryophytes can grow on any type of moist surface and can initiate land colonisation.

8. Why are bryophytes called amphibious plants?

Ans. Bryophytes grow on moist land and absorb moisture by root-like rhizoids. To complete their life cycle, they need at least a thin film of water for fertilisation of gametes. That is why bryophytes are popularly known as amphibious plants.

9. What are pteridophytes?

Ans. Pteridophytes are terrestrial, non-flowering plants having true roots, stems, leaves and vascular tissues and maintain sporophytic generation throughout the major part of their life cycle. Example-Marsilea sp., Selaginella sp.

10. What is a gametophore? Name the reproductive organs of moss and fern.

Ans. The gametophore is a structure, present in the gametophytic plant body of mosses and ferns, which bears the male and female sex organs.

Male and female reproductive organs of moss and fern are known as antheridium and archegonium respectively.

11. Mention two identifying features of dicotyledonous plants.

Ans. Two identifying features of dicotyledonous plants are [1] Seeds remain hidden inside fruit and each seed has two cotyledons. [2] Tap root system and dorsiventral leaves with reticulate venation are seen.

12. Mention two similarities between monocotyledonous and dicotyledonous plants.

Ans. Similarities between monocotyledonous and dicotyledonous plants are-[1] Both are angiospermic plants. [2] Sexual reproduction and fertilisation occur in both types. [3] Seeds of both type of plant groups contain cotyledon. [4] Both have well developed vascular system, that is made up of xylem and phloem.

Very Short Answer Type Questions

Multiple Choice Questions & Answers [MCQ]

1. Non-flowering photosynthetic plants belong to-

A. Pteridophyta

B. Fungi

C. Angiospermae

D. Gymnospermae

Ans. A

2. The vegetative body of thallophytic plants is called-

A. Rhizoid

B. Mycelium

C. Thallus

D. Viroid

Ans. C

3. Which one is an alga?

A. Pogonatum

B. Spirogyra

C. Dryopteris

D. Yeast

Ans. B

4. Which alga is used as a protein supplement?

A. Volvox

B. Spirogyra

C. Chara

D. Chlorella

Ans. D

5. The symbiotic association of an alga and a fungus is called-

A. Mycorrhiza

B. Lichen

C. Haustoria

D. None of these

Ans. B

6. Which one is the amphibian among plant kingdom?

A. Algae

B. Lichen

C. Bryophyta

D. Pteridophyta

Ans. C

7. The bryophyte, having thallus-like body is-

A. Moss

B. Liverwort

C. Hornwort

D. All of these

Ans. B

8. Gametophytic phase is predominant in the life cycle of-

A. Bryophyta

B. Pteridophyta

C. Angiosperms

D. Gymnosperms

Ans. A

9. Which of the followings is a bryophyte?

A. Sphagnum

B. Marsilea

C. Yeast

D. Laminaria

Ans. A

Answer in a single word or sentence

1. Members of which group of plants are not divisible into roots, stems and leaves?

Ans. Plant body of the members of thallophyta group are not divisible into roots, stems and leaves.

2. Name a thallus type of plant.

Ans. Spirogyra sp.-an alga

3. Name an alga which has spirally coiled chloroplast in its cells.

Ans. Spirogyra sp. is an alga that has spirally coiled chloroplast in its cells.

4. Name a filamentous alga having prokaryotic cells.

Ans. Nostoc is a filamentous alga, having prokaryotic cells.

5. Name the stored food of algae.

Ans. Starch

6. Name a colonial alga.

Ans. Volvox is a colonial alga.

7. Name a unicellular alga, which is now treated as a protist.

Ans. Chlamydomonas is a unicellular alga, which is now treated as a protist.

8. Name an alga that carries pyrinoid granules within chloroplast.

Ans. Spirogyra sp.

9. Which alga is commonly known as pond silk?

Ans. Spirogyra sp.

10. Which type of bryophytes form velvety thallus on moist soil?

Ans. Liverworts form velvety thallus on moist soil.

11. Name a thalloid bryophyta.

Ans. Riccia sp.

12. Which type of bryophytes are called liverworts?

Ans. Thalloid bryophytes like Riccia, Marchantia etc. called liverworts.

13. What is the name of the erect portion of moss?

Ans. The erect portion of moss is called gametophore.

14. What is the name of the fine root-like structure of a moss?

Ans. The fine root-like structure of a moss is called rhizoid.

15. Mention the function of rhizoids.

Ans. Rhizoids help to collect water, mineral salts from soil and affix the plant body to the soil.

Fill in the blanks

1. The body of thallophyta is called …………

Ans. Thallus

2. ………… are called photosynthetic thallophyta.

Ans. Algae

3. Riccia is commonly known as …………

Ans. Liverwort

4. Plant body of moss is …………

Ans. Gametophytic

5. Pteridophytes have ………… type of stem.

Ans. Rhizome

6. Tiny and fine leaves of ferns are called …………

Ans. Microphyllous leaves

7. Though cryptogams but ………… bear vascular tissue.

Ans. Pteridophytes/Ferns

8. True root, stem and leaves are first seen in …………

Ans. Pteridophytes/Ferns

State True or False

1. Cryptogams are non-flowering plant group.

Ans. True

2. Examples of phanerogams are gymnosperms and angiosperms.

Ans. True

3. Phanerogams do not produce seeds.

Ans. False

4. The main plant body of bryophytes is gametophytic.

Ans. True

5. Liverwort is a non-flowering tracheophyte.

Ans. False

6. Stem-like structure of a moss is called rhizoid.

Ans. False

7. Phyllid, the leaf-like structure of mosses, does not bear stomata.

Ans. False

8. Certain bryophytes have xylem-like water conducting tissue, called hydroid.

Ans. True

SUB-TOPIC – 3.4

CLASSIFICATION OF KINGDOM ANIMALIA

SUMMARY

Animals under kingdom Animalia are distributed in two groups-Chordates and Non-chordates.
The animals, devoid of notochord, are called non-chordates. Non-chordates are classified into ten different phyla. Those are-Porifera, Cnidaria, Ctenophora, Platyhelminthes, Nematoda, Annelida, Arthropoda, Mollusca, Echinodermata and Hemichordata.
Typical characteristic features of phylum Porifera are presence of numerous ostia and a large osculum in the body. Example-Spongilla, Sycon, etc.
Phylum Cnidaria has a large gastro-vascular cavity, jelly-like mesoglea in between ectoderm and endoderm and numerous cnidoblast cells in the body. Example-Hydra, Aurelia, etc.
Main identifying feature of phylum Ctenophora are eight equidistant meridional ciliary plates. Example-Beroe, Hormiphora, etc.
Phylum Platyhelminthes have flat tape-like body, made up of three distinct germinal layersectoderm, mesoderm and endoderm. They perform excretion by flame cells. Example-Taenia, Fasciola, etc.
Members of phylum Nematoda are characterized by long worm-like body covered with thick chitinous cuticle. They have typical pseudocoelom inside body. Example- Ascaris, Echinococcus etc.
Salient features of Annelida are presence of true coelom and numerous annulous metameres in the body. Example-Pheretima, Hirudinaria, etc.
Phylum Arthropoda are characterized by presence of hard exoskeleton and paired jointed appendages. Example-Periplaneta, Palaemon, etc.

Long Answer Type Questions

1. Schematically represent the classification of animal kingdom with one example each.

Ans. Schematic representation of the classification of animal kingdom.

2. Mention the identifying features of phylum Porifera. Give two examples with scientific names.

Ans. Identifying features of phylum Porifera

Body is multicellular, without well-developed tissue system.
Body is arranged in two layers external pinacoderm and internal choanoderm and jelly-like mesenchyme is present in between these two layers.
Exoskeleton is hard and rigid, made up of calcium or silicon-rich cells, called spongin fibres or spicules.
One large aperture, called osculum is present at the upper end of the body. There are numerous tiny pores, called ostia, spreaded all over their body.
Water flows continuously in the body through pores, interconnected canals and chambers.

Example with scientific names

Two examples of the members of phylum Porifera are Neptune’s cup (Poterion neptuni) and freshwater sponge (Spongilla lacustris).

3. Mention the identifying features of phylum Cnidaria. Give two examples with scientific names.

Ans. Identifying features of phylum Cnidaria

[1] Members of this group live in water.

[2] They have a soft diploblastic body, made up of ectoderm and endoderm. In between these two layers, an acellular jelly-like mesoglea is present.

[3] Radially or biradially symmetrical body, contain a gastrovascular cavity called coelenteron. This cavity has a single opening that is surrounded by tentacles.

[4] Typical stinging cells, called cnidoblasts, are present on the tentacles, equipped with a special stinging structure called nematocyst, which is used to capture prey and for self-defence.

Example with scientific names

Two examples of the members of phylum Cnidaria are hydra (Aurelia aurita).

4. Mention the identifying features of phylum Ctenophora. Give two examples.

Ans. Identifying features of phylum Ctenophora

[1] Body is diploblastic, made up of ectoderm and endoderm and bi-radially symmetrical. In between ectoderm and endoderm, a layer of jelly-like substance called mesenchyme is present.

[2] Body divisible into oral and aboral ends. The aboral end consists of a sensory structure, called statocyst.

[3] Eight quidistant longitudinal ciliary plates or comb plates are present on the body that help in locomotion.

[4] Typical adhesive cells, called colloblast cells or lasso cells are present in the tentacles. These colloblast cells help in capturing prey during predation.

Example of Ctenophores

Two examples of the members of phylum Ctenophora are Hormiphora plumosa and Beroe forskalii.

5. Mention the identifying features of phylum Platyhelminthes. Give two examples with scientific names.

Part Question, Mention two characteristic feature of Phylum Platyhelminthes.

Ans. Identifying features of phylum Platyhelminthes

[1] Body is dorsiventrally flat, so are called flatworms and externally covered by syncitial membrane. Their body is bilaterally symmetrical. [2] Body wall is composed of three germinal layersectoderm, mesoderm and endoderm. Hence, they are triploblastic. [3] Body cavity or coelom is absent. Body consist of a distinct head region and a prominent sucker at the mouth. [4] Except reproductive system, other organ systems are not well developed. Excretion occurs by flame cells or protonephridia. [5] All members of this group are hermaphrodite, i.e., bisexual. [6] They may be free-living or parasitic. Liver fluke

Example with scientific names

Two examples of the members of phylum Platyhelminthes are tapeworm (Taenia solium) and liver fluke (Fasciola hepatica).

6. Mention the identifying features of class Aves. Give two examples with scientific names.

Ans. Identifying features of class Aves

[1] The animals belonging this class are warm-blooded animals.

[2] Body is spindle-shaped and covered with feathers.

[3] Forelimbs are modified into wings.

[4] Their bones are hollow due to the presence of air cavities. This helps to reduce their weight and help in flying.

[5] Besides lungs, they have 9 air sacs, which help in flight.

[6] Urinary bladder, rectum and right ovary absent in order to reduce body weight.

[7] Teeth completely absent and jaws are modified into beaks. [8] They have four-chambered heart with two auricles and two ventricles.

Example with scientific names

Two examples of the members of class Aves are crow (Corvus splendens) and pigeon (Columba livia).

7. Mention the identifying features of class Mammalia. Give two examples with scientific names.

Part Question, Mention two characters of Class-Mammalia.

Ans. Identifying features of class Mammalia

[1] The animals under this class are warm-blooded animals and their bodies are bilaterally symmetrical.

[2] Body is covered with hair. Sweat and sebaceous glands are present in the skin.

[3] The female members of this group have milk-producing mammary glands, for nourishing their young ones.

[4] A pair of external ears or pinnae is present on either side of the head.

[5] Respiration occurs by a pair of lungs.

[6] They have two pairs of limbs, used for locomotion, digging, holding or feeding.

[7] They are viviparous animals, i.e., give birth to young ones.

[8] Heart is four-chambered with two auricles and two ventricles and has left aortic arch.

Example with scientific names

Two examples of the members of class Mammalia are man (Homo sapiens sapiens) and deer (Axis axis).

8. Give example of a vertebrate other than man. In which class does it belong to? Why do you put the animal in that class?

Ans.

Other than man, pigeon (Columba livia) is a vertebrate. It belongs to class – Aves.

Cause of putting pigeon in Class – Aves

[1] Pigeons are warm-blooded animals.

[2] Their body is spindle-shaped and covered with feathers.

[3] Their forelimbs are modified into wings.

[4] Their bones are hollow due to the presence of air cavities. This helps to reduce their weight and help in flying.

[5] Besides lungs, they have 9 air sacs, which help them to flight.

[6] In order to reduce their body weight urinary bladder, rectum and right ovary are absent in their body.

[7] Teeth completely absent and jaws are modified into beaks.

[8] They have four-chambered heart with two auricles and two ventricles.

For all these reasons, we put pigeon in class-aves.

Short Answer Type Questions

1. What are diploblastic animals?

Ans.Those animals, whose body consists of two germinal layers, i.e. ectoderm and endoderm, are known as diploblastic animals. Example-Hydra, etc.

2. What are triploblastic animals? Give Example.

Ans.Those animals, whose body consists of three germinal layers, i.e. ectoderm, mesoderm and endoderm, are known as triploblastic animals.

Example-Tapeworms, earthworms, etc.

3. What is meant by bilaterally symmetrical animals?

Ans.The animals, which when divided once along the central axis gives two similar halves, are called bilaterally symmetrical animals. ExampleCockroach, human, etc.

4. What is meant by radially symmetrical animals?

Ans. The animals, which when divided in any plane along the central axis gives rise to unlimited number of identical halves, are called radially symmetrical animals. ExampleStarfish, etc.

5. What is meant by asymmetrical animals?

Ans.The animals, which when divided along any plane of the body, does not give rise to equal halves, are called asymmetrical animals. Example-Amoeba, molluscs, etc.

6. Mention the names of non-chordate phyla.

Ans.Names of non-chordate phyla are – Porifera, Cnidaria, Ctenophora, Platyhelminthes, Nematoda, Annelida, Arthropoda, Mollusca, Echinodermata and Hemichordata.

7. What is spongocoel?

Ans.The single, large central body cavity of the poriferan is called spongocoel. Water enters this cavity through several tiny pores called ostia and exits through a large opening called osculum.

8. What is meant by canal system?

Ans.The animals under phylum Porifera have numerous pores all over the body. Through these pores water enters into the body and flows in all direction through a network of fine canals. This is called canal system.

9. What is mesenchyme and in which Phyla is enchyme and in which Phyla is it found?

Ans.Mesenchyme or mesohyl is a jelly-like layer with a few scattered cells and collagen fibres, present in between the two layers of cells of the body. This is found amongst the members of phylum Porifera and Ctenophora.

10. What are ostia and osculum?

Ans. Ostia: The animals under phylum Porifera possess numerous small pores all over their body which allow water to enter the body. These tiny pores are called ostia.

Osculum: The body cavity of the poriferans opens outside through a narrow circular opening, situated at the free end of their body. This opening is called osculum.

11. What is mesoglea?

Ans. Mesoglea is a completely non-cellular jellylike layer, typically seen in between ectoderm and endoderm layer of the animals under phylum Cnidaria.

12. What is cnidoblast cell?

Ans. Cnidoblast cell is a typical explosive epidermal cell, present in numbers on the tentacles of cnidarians. These cells carry huge secretory organelle, called nematocyst, which injects strong neurotoxin into the body of the preys and attackers.

13. What is nematocyst?

Ans. Nematocyst is a typical stinging cell, present in the cnidoblast of cnidarians. This is a vesicle with a hairlike sensory process ejecting, called cnidocil, which discharges strong paralysing material to the preys and attackers.

14. Write down the significance of the namesCnidaria and Ctenophora.

Ans. Naming of Cnidaria: Phylum Cnidaria has typical stinging cells, called cnidoblast, on their tentacles and on body surface. That is why this phylum is named as Cnidaria.

Naming of Ctenophora: In Greek, Ktenos means comb and Phoros beans bearing. Members of this phylum have eight equidistant meridional comblike ciliary plates on their body.

15. What are colloblast cells or lasso cells?

Ans. Colloblast cells or lasso cells are a kind of adhesive cells, present typically on the tentacles of the members of phylum Ctenophora. These cells are used to capture prey during predation.

16. What is metamere or somite?

Ans. The body of annelids are transversely divisible into a series of several similar ring-like segments. These are called somites or metameres.

17. What is combplate?

Ans. Locomotory organs of Ctenophora are the eight equidistant, comb-like, ciliary plates along meridional plane of the body. These are commonly called the combplates.

18. What is pseudocoelom?

Ans. The body cavity that is not lined by mesodermal tissue is called pseudocoelom. This type of body cavity is seen among Aschelminthes, like Ascaris, Echinococcus, etc.

19. Who are called Coelomates? Give example.

Ans. Coelomates: The groups of animals, who have their body cavity lined by mesodermal tissue are called Coelomates.

Example: Earthworm, human, etc.

20. Which phylum among Nematoda and Annelida is advanced and why?

Ans. Phylum Annelida have true coelom, closed circulatory system and typical excretory organs, therefore, from evolutionary point of view, phylum is regarded as an advanced one in comparison to phylum Nematoda.

21. What are ambulacra?

Ans. In phylum Echinodermata rows of tube feet remain arranged in oral plane of each arm along its medial axis. This axis is called ambulacrum, (plural: Ambulacra).

Very Short Answer Type Questions

Multiple Choice Questions & Answers [MCQ]

1. Multicellular animals without true tissues, belong to phylum-

A. Cnidaria

B. Porifera

C. Ctenophora

D. Protozoa

Ans. B

2. Which of the following phyla has numerous pores over its body to allow water to come inside?

A. Echinodermata

B. Mollusca

C. Porifera

D. Cnidaria

Ans. C

3. Which of the following features is absent in non-chordates?

A. Metameric segmentation

B. Bilateral symmetry

C. Axial skeleton

D. All of these

Ans. C

4. The animals which perform excretion by numerous nephridia, belong to phylum-

A. Echinodermata

B. Arthropoda

C. Annelida

D. Porifera

Ans. C

5. Marine animals which performs locomotion with the help of eight meridional cilliary plates, belong to phylum-

A. Cnidaria

B. Ctenophora

C. Mollusca

D. Echinodermata

Ans. B

6. Which of the following animals has a single body cavity?

A. Cnidaria

B. Ctenophora

C. Both A and B

D. None of these

Ans. C

7. The tiny pores through which water enters into the body of poriferans, are called

A. Stomodeum

B. Osculum

C. Ostia

D. Proctodeum

Ans. C

8. Flower vase-like body with a single opening at the top is seen in

A. Starfish

B. Hydra

C. Snail

D. Crab

Ans. B

9. Body is covered with thick chitinous exoskeleton in

A. Arthropoda

B. Mollusca

C. Porifera

D. Annelida

Ans. A

10. The group of animals possessing stinging cells on the body surface, belong to phylum

A. Echinodermata

B. Cnidaria

C. Ctenophora

D. Arthropoda

Ans. B

11. Placoid scale is seen in—

A. Rohu fish

B. Dolphins

C. Whales

D. Sharks

Ans. D

12. Unevenly divided tail fin is seen in

A. Shark

B. Rohu fish

C. Cat fish

D. Whale

Ans. A

13. Which of the following is never seen in fresh water bodies?

A. Poriferans

B. Echinoderms

C. Molluscs

D. Cnidarians

Ans. B

14. Which of the following is not a chordate?

A. Balanoglossus

B. Ascidia

C. Branchiostoma

D. Myxine

Ans. A

15. Flame cells, nephridia and green glands are the excretory organs of

A. Earthworm, cockroach and tape worm respectively

B. Tape worm, earthworm and prawn respectively

C. Prawn, butterfly and snail respectively

D. Starfish, jelly fish and prawn respectively

Ans. B

16. Swim bladder is typically seen in-

A. Bony fishes

B. Cartilaginous fishes

C. Seals

D. Dolphins

Ans. A

17. Which of the following is an amphibian feature?

A. Naked glandular skin

B. Three-chambered heart

C. Aquatic larva

D. All of these

Ans. D

18. Reptiles have –

A. Epidermal scales

B. Dermal scales

C. Glandular skin

D. None of these

Ans. A

19. Beaks are the modification of-

A. Cranium

B. Teeth

C. Jaws

D. Tongue

Ans. C

20. Body hair, sweat glands and sebaceous glands are seen in that class of animals, which possess-

A. External pinnae

B. Muscular foot

C. Clawed digits

D. Beaks

Ans. A

21. Radula is the-

A. Feeding organ of snails

B. Biting organ of starfishes

C. Swimming organ of squids

D. Feeding organ of insects

Ans. A

22. Clawed digits are seen amongst-

A. Amphibia, reptilia and aves

B. Reptilia, aves and mammalia

C. Mammalia, amphibia and aves

D. Mammalia and aves only

Ans. B

Answer in a single word or sentence

1. In triploblastic animals, which germinal layer is present in between ectoderm and endoderm?

Ans. In triploblastic animals, mesoderm layer is present in between ectoderm and endoderm.

2. Name a phylum in which mesenchyme is present in between ectoderm and endoderm?

Ans. In phylum Porifera, mesenchyme is present between ectoderm and endoderm.

3. Name an animal of phylum Porifera.

Ans. Sycon gilatinosum

4. Write scientific name of an organism, which has choanocyte.

Ans. Sycon gilatinosum

5. To which phylum does ‘Neptune’s cup’ belong?

Ans. Phylum Porifera

6. In which phylum is gastro-vascular cavity found?

Ans. Phylum Cnidaria

7. How many germinal layers are present in animals under phylum Cnidaria?

Ans. Two layers, ectoderm and endoderm

8. In which phylum polyp and medusa stages are found in life cycle?

Ans. Cnidaria

9. Name the prey-capturing cells present in the tentacles of Hydra.

Ans. Cnidoblast cells or cnidocyte

10. How many germinal layers are present in the animals of phylum Ctenophora?

Ans. Three germinal layers, namely ectoderm, mesoderm and endoderm.

11. Name the animal in which statocyst is present?

Ans. Statocyst is present in different animals of phyla Cnidaria, Ctenophora, Mollusca, Echinodermata. (Land snail, Beroe, etc.)

12. In which phylum does Hormiphora belong to?

Ans. Ctenophora

13. What is flame cell?

Ans. Excretory organ of Platyhelminthes is flame cell.

14. In which phylum animals do possess many ring-like metameres in their body?

Ans. Annelida

15. What is parapodia?

Ans. The paired locomotory organs of certain annelids like Nereis, are called parapodia.

16. In which phylum does earthworm belong to?

Ans. Annelida

17. Write down the scientific name of earthworm.

Ans. Metaphira posthuma (old name Pheretima posthuma).

18. In which phylum does leech belong to?

Ans. Phylum Annelida

19. Name the blood-filled body cavity of arthropods.

Ans. Haemocoel

20. What is Haemocoel?

Ans. The blood-filled coelom, which is commonly found amongst arthropods, is called Haemocoel.

21. In which phylum, is ecdysis seen?

Ans. Phylum Arthropoda

22. In which phylum and in which animal is bookgill found?

Ans. Book-gill is found among prawns, crabs under phylum Arthropoda.

23. In which animal and phylum do book-lung act as respiratory organ?

Ans. In spiders, scorpions, etc. under phylum Arthropoda, book-lung acts as respiratory organ.

24. In which animal and phylum does Malpighian tubule act as excretory organ?

Ans. Malpighian tubule acts as excretory organ in cockroach under phylum Arthropoda.

25. In which animal and phylum does coxal gland act as excretory organ?

Ans. In scorpions under phylum Arthropoda coxal gland acts as excretory organ.

26. Which phyla do include prawn and tape-like worms?

Ans. Prawn belongs to phylum Arthropoda and tape-like worms belong to phylum Platyhelminthes.

27. In which animal and phylum are Ctenidia found?

Ans. Ctenidia are found in snails under phylum Mollusca.

28. In which phylum does Achatina fulica belong to?

Ans. Achatina fulica belongs to phylum Mollusca.

29. Name two animals, which do not have any shell outside their body?

Ans. Octopus and Sepia do not have shell outside their body.

30. By which material is the endoskeleton of echinoderms composed of?

Ans. Calcium carbonate

31. Which is the locomotory organ of starfish?

Ans. Tube foot

32. In which phylum is ambulacra found?

Ans. Phylum Echinodermata

33. What is proboscis or prosome?

Ans. The anterior portion of the body of hemichordates is known as proboscis or prosome.

Fill in the blanks

1. Members of the phylum ……… do not possess any of the three germ layers.

Ans. Porifera

2. Poriferans release water from the body through a large opening called ………

Ans. Osculum

3. Members of the phylum ………… perform locomotion by the help of soft muscular foot.

Ans. Mollusca

4. Choanocyte cells are seen in ……….

Ans. Porifera

5. The visceral mass of Mollusca remains covered with ……….

Ans. Mantle

6. Hydra and sea anemone belong to the phylum ………..

Ans. Cnidaria

7. The stinging cells present in the body of animals under phylum Cnidaria are called ……….

Ans. Agnatha

8. Single nostril is seen in the members of superclass ……….

Ans. Porifera

9. Ostia and osculum are the characteristic feature of phylum ……….

Ans. Cnidoblast cells

10. ………. is a sedentary animal.

Ans. Sponge

11. Cnidoblast cell is found in ……….

Ans. Hydra

12. A fresh water Cnidarian is …………

Ans. Hydra

13. One example of sub-phylum Urochordata is

Ans. Flame cell

14. Excretory organ of flat worms is

Ans. Round worm

15. An animal with pseudocoelome is ……….

Ans. Annelida

State True or False

1. Insects possess three pairs of jointed limbs.

Ans. True

2. Mammalian heart is four chambered.

Ans. True

3. Frog is a warm-blooded animal.

Ans. False

4. In birds, the forelimbs are modified into wings.

Ans. True

5. Members of class Chondrichthyes are all bony fishes.

Ans. False

6. Presence of notochord is the characteristic feature of the phylum Echinodermata.

Ans. False

7. Members of phylum Ctenophora possess combplate.

Ans. True

8. Ascaris is a Nematode.

Ans. True

9. The body of nematoda remains covered by cuticle.

Ans. True

10. The exoskeleton of arthropods and cell wall of fungi contains chitin.

Ans. True

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