WBBSE 9th Class Science Solutions Life Science & Environment Chapter – 2 Levels of Organisation of Life

1. Synthesis: Most of the vitamins are synthesised in plant body. A few are synthesised in animal body (such as Vitamin A, D, K and B_₁2).
2. Daily requirement: Vitamins act in a very little quantity; therefore, daily requirement of vitamins is very low.
3. Storage: Vitamins are stored in very little quantity. Fat-soluble vitamins are stored in adipose tissue below the skin. Vitamin C is stored in adrenal cortex.
4. Fate: Vitamins are not digested. These are absorbed intact. However, during metabolic processes these are partially denatured.
5. Solubility: Some vitamins like vitamin B and C are soluble in water. Vitamin A, D, E and K are soluble in fat and organic solvents, like-ether, chloroform, etc.
6. Help in enzymatic activity: Some vitamins act as coenzymes, thus play important role in enzymatic activity.
7. Role in metabolic reaction: Requirement of vitamins is directly proportional to metabolic rate. Therefore, daily requirement of vitamins of a physically active person or a pregnant woman is higher than a normal person.

TOPIC – 2

CELL

SUMMARY

• Cell is the structural and functional unit of life. The cell body contains cytoplasm, surrounded by a cell membrane. The cytoplasm carries a nucleus and several other organelles.
• Plant cell has a rigid non-living wall outside the cell membrane. It protects the cell from external injury.
• Singer and Nicolson first proposed the fluid mosaic model of cell membrane. According to this model, several protein molecules remain scattered in a fluid-like lipid bilayer to constitute the cell membrane. Cell membrane protects cytoplasm and takes part in transportation of different cellular materials through it.
• Cytoplasm is a viscous, granular, intracellular matrix. Cytoplasm and nucleus together constitute protoplasm. It is the site for cellular metabolism.
• Nucleus is a eukaryotic cell organelle. DNA present in its chromatins takes part in control and transmission of genetic characters from parents to offsprings.
• Mitochondria are double membrane-bound cytoplasmic organelles, which take part in cellular respiration.
• Plastids are typical plant cell organelles. Based on presence or absence of pigments in it, plastids are of three types-(i) Green coloured chloroplast or chloroplastid contains green chlorophyll pigment and takes part in photosynthesis, (ii) Chromoplast or chromoplastids carry yellow, orange, red or other coloured carotenoid pigments which are responsible for colour of different parts of plants other than green, (iii) Leucoplasts are colourless as they carry stored food rather than pigments.

Long Answer Type Questions

1. Middle lamella: It is a jelly-like intercellular matrix, present in between primary cell wall of the two adjacent cells. It is composed of calcium and magnesium pectate.
2. Primary cell wall: The primary cell wall is the outermost layer of cell wall. It is comparatively thin, permeable and elastic. Mainly it is composed of cellulose and hemicellulose.
3. Secondary cell wall: This layer is situated in between the primary cell wall and cell membrane. This layer is mainly built by deposition of lignin, suberin, hemicellulose, etc. from the cell. Therefore, its thickness increases with the age of the cell.

1. Chloroplast: This type of plastids contains green pigments, like-Chlorophyll a and Chlorophyll b, xanthophyll (yellow pigment) and carotene (orange pigment). This type of plastids have varied size and shapes. Each of these plastids has grana and stroma in the inner chamber.
2. Chromoplast: These plastids carry several pigments other than green. These are-orangecoloured carotene, yellow-coloured xanthophyll, red-coloured phycoerythrin, blue-coloured phycocyanin, etc. Chromoplasts are spherical, rod-shaped or star-shaped cell organelles.
3. Leucoplast: These plastids do not possess any pigment, hence are colourless. These are spherical, oval or rod-shaped structures. Based on the content of food stored in it, leucoplasts are of three types-[A] Amyloplast (stores starch), [B] Proteinoplast or Aluroplast (stores protein) and [C] Elaioplast (stores fats).

1. Chloroplast: Green pigment chlorophyll present in it absorbs sunlight and directly helps in photosynthesis to produce simple sugar from water and carbon dioxide.
2. Chromoplast: These types of plastids create the colour of flowers and fruits. These plastids indirectly help in pollination by creating attractive colours of flower petals.
3. Leucoplast: Different types of leucoplasts store food materials like starch, protein granules and oil droplets.

Short Answer Type Questions

Ans.Plasmodesmata: Plasmodesmata are the ultrafine cytoplasmic connection through the fine pits on the cell wall between two adjacent plant cells.

Function: Intercellular transport is the main function of plasmodesmata.

Very Short Answer Type Questions

Multiple Choice Questions & Answers [MCQ]

Answer in a single word or sentence

Fill in the blanks

State True or False

TOPIC – 3

TISSUE

SUB-TOPIC – 3.1

PLANT TISSUE AND ITS DISTRIBUTION

SUMMARY

• In multicellular organisms, tissues can be observed. Tissue is a cellular organizational level between cells and a complete organ. A group of cells that possesses a similar structure and perform a specific function, is known as tissue.
• On the basis of kind of cells present, the plant tissues are mainly of two types: (1) Meristematic tissue: The cells of this tissue divide actively. (2) Permanent tissue: The cells lost the ability of division, constituting this tissue, are completely grown and have .
• On the basis of the structure of constituting cells, permanent tissues are of two types- (1) Simple permanent tissue, (2) Complex permanent tissue.
• Simple permanent tissue consists of group of cells which are similar in origin, structure and function. Simple permanent tissue can be of three types. They are—parenchyma, collenchyma and sclerenchyma.
• Complex permanent tissue composed of more than one type of cells which work together as a unit. The complex permanent tissue in plants are xylem and phloem.
• Xylem helps in conduction of water and solutes. Hard, lignified wall of the cells of xylem tissue signifies their mechanical property.
• Pholem carries the food prepared by the leaves to different parts of the plant.

Long Answer Type Questions

1. What is meant by tissue? How plant tissues can be classified into different types?

Ans. Tissue

Tissue is the assemblage of a number of structurally similar or dissimilar cells having same origin and function.

Classification of different plant tissues

2. What is meant by meristem or meristematic tissue? Describe the characteristic features of the meristematic tissue with a simple diagram. 

Ans. Meristem or meristematic tissue

Meristems or meristematic tissues are cells or group of cells that are capable of undergoing cell division.

Distribution of meristematic tissues

The characteristic features of meristematic tissue are as follows-

[1] Cells are living, undifferentiated, polygonal, spherical or oval in shape.

[2] Cells are densely packed and without intercellular spaces.

[3] Cell wall is thin, made up of cellulose.

[4] Nucleus is large and distinct.

[5] Cytoplasm is dense, vacuoles generally absent.

[6] The cells are capable of undergoing cell division.

3. Describe the distribution of different meristematic tissues with their functions and support your answer with diagram

Ans. Distribution of meristematic tissues 

Based on occurrence, meristematic tissues can be sub-divided into three types, which are as follows-

1. Apical meristem: It occurs at the tip of roots and shoots. Function: Apical meristem gives rise to primary plant body and helps the root and shoot of the plant to grow in length.

2. Intercalary meristem: It occurs near the nodes of growing shoots, in between two layers of permanent tissues.

Function: This makes the young internodes longer and also helps in the growth of leaves.

3 Lateral meristem: It occurs along the lateral position of roots and stems of higher plants. It divides laterally and makes the plant thicker. It is of two types-[A] Vascular cambium (fascicular cambium): It occurs within vascular bundle. [B] Cork cambium (phellogen): It occurs outside vascular bundle.

Function: Vascular cambium helps in formation of secondary xylem and secondary phloem tissues and cork cambium is responsible for secondary growth that replaces the epidermis in roots and stems.

4. What is meant by permanent tissue? Mention its distribution, characteristics and functions. 

Ans. Permanent Tissue

The plant tissues in which cells have lost their capability of undergoing cell division are known as permanent tissues.

Distribution of permanent tissue

According to the function, permanent tissues are located in various region within a plant body. simple permanent tissues are found below the epidermis. Parenchyma is found in mesophyll of leaves and in the cortex of stem and root. Collenchyma is generally found in the leaf stalks and leaf midribs. Sclerenchyma is found in stems around vascular bundle, hard covering of seeds and nuts and in the leaf veins. Complex permanent tissues can be found throughout a plant body.

Characteristics of permanent tissue

[1] Cells of these tissues do not divide any further. [2] These are mature cells, so they have attained definite size, shape, structure and perform a particular function. [3] Cells have larger vacuoles. Intercellular spaces are often present. [4] Cell walls are comparatively thick. Often ornamentations are present on cell wall. [5] These tissues comprise of either dead or living cells. In living cells, smaller nucleus with reduced protoplasm is observed. [6] Metabolic rate within the cells of this tissue is slower in comparison to that of meristematic cells.

Function

These tissues are involved in protection, support, transportation or secretion.

5. Mention the living and non-living components of xylem. Write down its function.

Ans. Components of Xylem

Xylem has four typical components. These are – tracheid, tracheae or vessels, xylem parenchyma and xylem fibres. Among them, xylem parenchyma is the living component of xylem, where as, the rests are non-living components.

Characteristic features of xylem components

The characteristic features of xylem components are. as follows-[1] Tracheids are dead, elongated cells with two pointed ends. Unevenly lignified thickening of walls create different patterns. Pits are present in the cell wall. These cells take part in water transportation through out the plant body. [2] Vessels or tracheae are long, tubular dead cells without end walls. Lumen is wider than that of tracheids. The wall of the vessels possess many pits. These cells also carry sap. Numerous cells are arranged in a row to form long continuous vessels. [3] Xylem fibres are composed of dead cells, which are very thin & long with pointed ends. Cell wall of xylem fibre is thick with a narrow lumen. These cells provide mechanical strength and rigidity to the plant body. [4] Xylem parenchyma is the only component of the xylem tissue which is composed of living cells. It has thin cell wall and it contains protoplasm.

6. Give a brief description of the structure of trachea. Mention the occurrence and functions of trachea. 

Ans. Structure of tracheae or vessels

The structure of tracheae is as follows-[1] These cells are dead, long and tubular in shape with completely or partially open ends. [2] The wall is lignified with bordered pits. Ornamentations are often found on the wall due to uneven thickening. [3] The lumen present here, is the widest among, all xylem components. [4] Several tracheal cells remain arranged one after another to form a continuous tube due to the dissolution of end walls.

Occurrence of tracheae or vessels

These xylem components occur in all angiosperms and a gymnosperm named Gnetum.

Functions of trachea

The functions of trachea are as follows-[1] It transports sap from root to leaves. [2] Trachea provides mechanical support to the plant body.

7. Give a brief description of the structure Xylem Parenchyma. Mention its occurrence and functions. 

Ans. Structure of xylem parenchyma

The structure of xylem parenchyma is as follows-[1] These are living cells with cytoplasm and small nucleus. [2] Cell wall is thin and composed of cellulose. [3] The cells are almost isodiametric and their lateral walls have few simple pits.

Occurrence of xylem parenchyma

Xylem parenchyma is present in the vascular bundle of all angiosperms and most of the gymnosperms, except pines.

Functions of xylem parenchyma

The functions of xylem parenchyma are as follows-[1] It helps in transportation of sap and also helps in lateral transportation. [2] It stores nutrients like carbohydrates, fats and excretory matters like tannin, inorganic crystals, etc.

8. Give a brief description of the structure of Xylem fibre. Mention its occurrence and functions. Aption of th of Xylem fibre. 

Ans. Structure of xylem fibres

The structure of xylem fibres is as follows-[1] The cells of xylem fibre are dead, very fine with pointed ends. [2] Cells have very narrow lumen. [3] Cell wall is very thick due to heavy lignification and rigid with both simple and bordered pits. [4] Fibres are of two types-libriform fibre and tracheid fibre.

Occurrence of xylem fibres

Xylem fibres are present in vascular bundle of all angiosperms and most of the gymnosperms, except pines.

Functions of xylem fibres

The functions of xylem fibres are a follows-[1] These provide mechanical support to plant body. [2] These also store food material and certain excretory matters.

9. What is phloem? Describe the distribution, characteristics and function of phloem.

Ans. Phloem

The organic food conducting complex tissue in vascular plants is known as phloem. These are composed of four elements-[1] sieve tubes, [2] companion cells, [3] phloem fibre or bast.fibre, [4] phloem parenchyma.

Distribution/Location

Phloem is present in vascular bundles of root, stem and leaves.

Characteristics

[1] These are complex, living permanent tissue. [2] All the cell elements of this tissue are living except phloem fibre. [3] Cell wall is thin, composed of cellulose except phloem fibre.

Function

Main functions of phloem are the conduction of food matters from leaves to different regions of plant body and its storage.

10. Describe the characteristic features of these components.

Ans. Characteristic features of phloem components

The characteristic features of phloem components are as follows- [1] Sieve tubes are living cylindrical cells with perforated end walls, called sieve plates. Nucleus is absent in mature cells. Several sieve tubes are arranged in a row forming a long tube. It helps in transportation and storage of food. [2] Companion cells are lens-shaped cells with prominent nucleus and dense cytoplasm. They are present on either side of sieve tube. These help sieve tube in tranporation of food. [3] Phloem parenchyma has granular cytoplasm and thin cell wall made up of cellulose. This component of phloem stores organic and ergastic materials. [4] Phloem fibre is the only non-living component of phloem. It is elongated with lignified walls. Pits are present in the cell wall. Fibres provide mechanical support to plant parts.

Short Answer Type Questions

1. Mention the correlation amongst cells, tissues, organs and body.

Ans. Cells are the structural and functional unit of living body. Cells of same origin and function having similar or dissimilar structures form a tissue. One or more types of tissue when unite to perform a specific function, form a tissue system. Several tissue systems constitute an organ and various form a body. organs

Cell → Tissue → Organ → Organ system → Organism

2. What is the utility of tissues in multicellular organisms?

Ans. Different utility of tissues in multicellular organisms are as follows-[1] Tissue brings division of labour to increase efficiency. [2] Tissues become organised to form organs and organ systems. [3] It decreases the work load of individual cell. [4] Chances of survival of the organisms increase due to higher efficiency and better organisation.

3. Represent the classification of meristematic tissue based on position, origin and function in the form of a chart. 

Ans. We can classify meristematic tissue in the following way-

4. Mention the occurrence of parenchyma cells.

Ans. The occurrence of parenchyma tissue is as follows [1] It is seen in the epidermis of all plant parts. [2] It is present in ground tissue of plants including cortex, medulla and medullary rays. [3] Mesophyll tissue of leaves is composed of parenchyma. [4] It occurs in endosperm of seeds.

5. Where do you find collenchyma tissue?

Ans. Collenchyma tissue is mainly found in the hypodermis of stem. Midrib and petiole of the leaves and peduncle of flowers are made up of collenchyma.

6. Mention the different types of sclerenchyma, based on their features?

Ans. Features of different types of sclerenchyma are as follows-[1] Sclerenchyma fibres are long and narrow cells with pointed ends. [2] Sclereids are broad with thick walled cells which occur singly or in small groups.

7. Where do you find sclerenchyma tissue in a plant?

Ans. Components of sclerenchyma are found in the following parts of plant-[1] Sclerenchyma fibres are present in the hypodermis, cortex, vascular bundles and pericycle. [2] Sclereids are found in seed coats.

8. Why are some specific types of sclereids called stone cells? 

Ans. The deposition of lignin, cutin and suberin on the cell wall of some short and oval or spherical shaped sclereids, makes them hard, like stones. The lumen of such cells are almost squeezed due to the deposition. That is why, these special type of sclereids are called stone cells. Stone cells are responsible for providing mechanical support to the plants.

Very Short Answer Type Questions

Multiple Choice Questions & Answers [MCQ]

1. Which of the following does not have a tissue system?

A. Amoeba

B. Volvox

C. Sponges

D. All of these

Ans. D

2. An organism possesses different types of tissues and organs due to-

A. Organogenesis

B. Differentiation

C. Cell division

D. None of these

Ans. B

3. Cells of a tissue always have-

A. Similarity in size and shape

B. Same life span

C. Same function

D. Different origin

Ans. C

4. Cells of meristematic tissues are-

A. Of same size and shape

B. Capable of division

C. Undifferentiated

D. All of these

Ans. D

5. Meristematic tissues are seen in-

A. Green leaves

B. Matured fruit

C. Root tip

D. Shoot

Ans. C

6. Stems of trees become thick by the activity of-

A. Lateral meristem

B. Intercalary meristem

C. Primary meristem

D. Apical meristem

Ans. A

7. intercalary meristem is found in-

A. Root apex

B. Stem apex

C. Nodes

D. Internodes

Ans. D

8. A tissue has cells with no intercellular space and vacuole in cytoplasm. This tissue is a-

A. Xylem tissue

B. Parenchyma tissue

C. Meristematic tissue

D. Collenchyma tissue

Ans. C

9. Cells of a tissue having a large and prominent nucleus and are capable of undergoing division can be identified as a-

A. Meristem

B. Parenchyma

C. Collenchyma

D. Sclerenchyma

Ans. A

10. Cells of this tissue are thin-walled, densely packed, capable of undergoing division and are located at the tip of roots. This is-

A. Parenchyma

B. Collenchyma

C. Intercalary meristem

D. Apical meristem

Ans. D

11. Intercalary meristem remains-

A. At the apex of shoots and roots

B. In vascular bundle

C. In between two permanent tissue layers

D. On the surface of plant body

Ans. C

12. Rapid elongation of a bamboo stem occurs due to the activity of –

A. Lateral meristem

B. Intercalary meristem

C. Apical meristem

D. Cambium

Ans. B

13. Formation of bark involves-

A. Apical meristem

B. Intercalary meristem

C. Vascular cambium

D. Cork cambium

Ans. D

14. Permanent tissues are composed of-

A. Undifferentiated cells

B. Identical cells

C. Growing cells

D. Matured cells

Ans. D

Answer in a single word or sentence

1. Which type of meristem occurs along the longitudinal plane of the plant body?

Ans. Lateral meristem

2. Which type of meristem is seen in the leafbase of pine?

Ans. Intercalary meristem

3. Which meristem helps in increasing girth of the plant?

Ans. Lateral meristem

4. Which type of tissue is the cork cambium?

Ans. Secondary meristematic tissue

5. What is the other name of cork cambium?

Ans. Phellogen

6. From which type of tissue does permanent tissue develop?

Ans. Permanent tissue develops from meristematic tissue.

7. Which type of parenchyma is involved in holding photosynthesis within it?

Ans. Chlorenchyma

8. How do the large air-filled intercellular spaces of parenchyma tissue in petioles of lotus plant help it?

Ans. The large air-filled intercellular spaces of parenchyma tissue in petioles of lotus plant help it to maintain its buoyancy and to float on water.

9. Name the cells of parenchyma tissue in which plants store their excretory matter.

Ans. Idioblast cells of parenchyma tissue

10. Identify the main types of tissue present pith of stem and husk of coconut.

Ans. In the pith of stem, parenchyma tissue and in husk of coconut, sclerenclyma tissue is present.

11. What is chlorenchyma?

Ans. The parenchyma tissue, carrying chloroplastids and acting as the site of photosynthesis is known as chlorenchyma.

12. Which type of tissue in fruits form roughage of our food diet?

Ans. Fruits containing sclerenchyma tissue, form roughage of our food diet.

13. Which type of sclerenchyma cells make the fruits like guava, pear, etc. harder?

Ans. Sclereid cells

14. Which simple permanent tissue is responsible for adding mechanical strength to the plant body?

Ans. Sclerenchyma tissue

15. Which tissue is predominant in a hard woody plant part?

Ans. Sclerenchyma tissue

16. Which plant tissue is involved in ascent of sap?

Ans. Xylem is involved in the ascent of sap.

17. Which cells of xylem exclusively provide mechanical support to the plant body?

Ans. Xylem fibres

18. Which tissue is also known as leptome?

Ans. Phloem tissue

19. Which cell of phloem takes part in transportation of food?

Ans. Sieve tubes

20. Which cells do not directly take part in transportation of food in plants but help in this process?

Ans. Companion cells

21. What do companion cells do?

Ans. Companion cells play supporting role in the conduction of food through sieve tubes.

22. Which type of cambium is also known as fascicular cambium?

Ans. Vascular cambium

23. What is dendrochronology?

Ans. The science that determines the age of tree.

24. What is meant by simple permanent tissue?

Ans. Simple permanent tissues consist of a group of similar type of cells performing the same function.

25. What is sclerenchyma fibre?

Ans. Long and fine sclerenchyma cells, with pointed ends and pitted wall, are known as sclerenchyma fibres.

26. Where does sclerenchyma cells occur?

Ans. Sclerenchyma cells occur in the hypodermis and pericycle of stem. These are seen in vascular bundle and bundle cap of dicot plants.

Fill in the blanks

1. The term ’tissue’ was coined by ……….

Ans. Bichat

2. The phenomenon by which a mass of cells take up definite structure and function is called ………..

Ans. Differentiation

3. Organisation of tissue is absent in ……… organisms.

Ans. Unicellular

4. Study of tissue is called ……….

Ans. Histology

5. ………. is the living plant tissue that is devoid of intercellular spaces.

Ans. Meristem

6. The example of secondary meristematic tissue is …………

Ans. Cork cambium

7. The outer layer of this parenchyma is called ……..

Ans. Pericycle

8. Pith is composed of ………..

Ans. Parenchyma

9. Thickening in collenchyma is consisted of ………. and pectin.

Ans. Cellulose

10. Casparian strips have compound ……….

Ans. Lignin

State True or False

1. Sieve tubes are unicellular.

Ans. False

2. Intercellular spaces can be found in meristematic tissue.

Ans. False

3. Permanent tissue differentiates into meristematic tissue.

Ans. False

4. All types of sclereids are called as stone cells.

Ans. False

5. Gnetum is the only gymnosperm where companion cells are present in phloem.

Ans. True

6. Phloem parenchyma is absent in monocotyledonous plants.

Ans. True

7. Apical meristem is responsible for growth of plant along the length.

Ans. True

8. Connective tissue is actually one type of parenchyma without intercellular space found in xylem and phloem.

Ans. True

9. The only dead component of phloem is sieve tube.

Ans. False

SUB-TOPIC – 3.2

TISSUE: ANIMAL TISSUE AND ITS DISTRIBUTION

SUMMARY

• On the basis of structure and function, four different types of tissues are recognised in higher animals and human beings. They are-(1) Epithelial tissue, (2) Connective tissue, (3) Muscular tissue and (4) Nervous tissue.
• Epithelial tissue is a layer of cells which covers our all free surface either externally or internally.
• Connective tissue normally connects different tissue systems.
• Muscular tissue is a contractile tissue consisting of large elongated cells or fibres. The cytoplasm of muscle cell contains a large number of longitudinal fibrils called myofibrils. The cytoplasm is called sarcoplasm and cell membrane is called sarcolemma. Three types of muscular tissues are there-(1) Striated muscles, (2) Unstriated muscles, (3) Cardiac muscles.
• Nervous tissue responsible for excitement and conduction of nerve impulse. Nervous tissue is composed of bunch of neurones. Each neurone consists of three parts-(1) Cell body, (2) Dendron, (3) Axon.
• Acetylcholine, Noradrenaline, GABA, Dopamin are the examples of neurotransmitter.

Long Answer Type Questions

1. Describe the structure of epithelial tissue. Mention its functions.

Ans. Structure of epithelial tissue

[1] The cells are present on a basement membrane made up of collagenous materials. [2] Cells are densely packed and are joined together by mucoproteins (special type of glycoprotein). [3] Cells of this tissue are either arranged in a single layer or in multilayers. [4] Cells do not get direct blood supply. They receive oxygen and nutrients from underlying tissues.

Functions of epithelial tissue.

[1] Epithelial tissue provides protection to animal body and its various organs. [2] Epithelial tissue like squamous epithelium, takes part in gaseous exchange. [3] Columnar epithelial cells help in absorption and secretion. [4] Certain cuboidal and glandular epithelial cells secrete enzymes and hormones.

2. Mention the distribution of connective tissue. Briefly mention the structure of connective tissues. 

Ans. Distribution of connective tissue

[1] Areolar tissue is present below skin, between muscles, outer coatings of nerves and walls of blood vessels. [2] Fibrous tissues are present in tendons, ligaments, walls of artery, trachea and larynx. [3] Adipose tissue is found below skin, mammary glands, surrounding the vital organs like heart, kidney, etc. [4] Bones and cartilages are found in the skeletal parts. [5] Blood and lymph are present in the circulatory system.

Structure of connective tissue

[1] Connective tissue originates from the mesoderm layer of the embryo. [2] It possesses fewer cells, which remain loosely placed in the intercellular matrix. [3] Cells of connective tissue are of various types with different size, shape, intra and intercellular components and functions. [4] Some fibrous materials like collagen, elastin etc. may be present in the matrix. [5] The matrix may be soft, jellylike (areolar and adipose tissue), liquid (blood, lymph), rigid (bone), elastic (cartilage).

Short Answer Type Questions

1. What is meant by epithelial tissue?

Ans. The tissue, which typically covers the outer surface of the body as well as the inner and outer lining of internal organs, is known as epithelial tissue. It consists of one or more cell-layers.

2. What is basement membrane? What does it do? 

Ans. Basement membrane: Basement membrane is a typical acellular layer of epithelial tissue, composed of materials, somewhat similar to matrix of connective tissue.

Function: Basement membrane holds the epithelial cells on it. It also helps the epithelium to remain attached to the surface of the connective tissue layer below it.

3. Write the different types of epithelial tissue.

Ans. It is of three types-[1] Surface protective epithelium, [2] Glandular epitheluim, [3] Sensory or neurosensory epithelium.

Surface protective epithelium is also three types(a) Simple, (b) Stratified, (c) Pseudostratified.

4. Mention the types of simple epithelial tissues.

Ans. Simple epithelial tissue are of different types. These are [1] Squamous epithelium, [2] Cuboidal epithelium, [3] Columnar epithelium, [4] Ciliated epithelium.

5. Mention the distribution of epithelial tissue.

Ans. Epithelial tissue is present on the outer surface of the body (skin) and the inner lining of oral cavity, intestine, blood vessels, nasal passage, respiratory tracts, alveoli, renal tubules, urinary bladder, uterus, fallopian tube and different glands.

6. Mention the two function of simple epithelial tissue. 

Ans. Two functions of simple epithelial tissue are[1] The tissue helps in exchange of gaseous and liquid substance. [2] It protects the organs from friction.

7. Mention the characteristics, distribution and function of simple squamous epithelium.

Ans. Characteristics: [1] Cells of the tissue are larger, flattened and elongated. [2] Nucleus are flattened and oval. [3] The cells remain arranged on basement membrane.

Distribution: Present in alveoli, peritonium, pleura, loop of Henle and Bowman’s capsule of Kidney.

Function: [1] The tissue helps in the exchange of gaseous and liquid substance. [2] Helps in filtration. [3] Protects the body from microorganisms.

8. Mention the characteristics, distribution and function of cuboidal epithelium.

Ans. Characteristics: [1] The cells of the tissues are equal in length and breadth. [2] the nucleus of the cell is oval shaped. [3] Upper surface of the cell is polygonal.

Distribution: Present in renal tubule, salivary glands, thyroid gland.

Function: Helps in secretion and defense.

9. Mention the characteristics, distribution and function of columnar epithelium.

Ans. Characteristics: [1] Length of the cell is greater than the breadth. [2] Cells are remain arranged on the basement membrane hence called columnar tissue. [3] Nucleus is oval and large in size. [4] Cytoplasm is reticular.

Distribution: Present in stomach, small intestine, large intestine and in certain glands.

Function: [1] Secretion and defense. [2] Protection.

10. Mention the characteristics, distribution and function of ciliated epithelium.

Ans. Characteristics: [1] The cells of this tissue is somewhere columnar, somewhere cuboidal. [2] The cells of this tissue bearing 28-30 hairlike appendages at their surface. [3] Cilia is arise from basal part.

Distribution: Present in alveoli and its’ adjacent part, uterus, oviduct, ependymal cells (spinal cord). Function: [1] Clears mucous, dust particles, different types of microbes from the respiratory tract. [2] The cell helps to expel ovum and spermatozoa.

11. Mention the characteristics, distribution and function of stratified or compound epithelium.

Ans. Characteristics: [1] The tissue is formed by 3 to 4 cell layers. [2] Cells of the upper layer are large, flattened and quadrangular. [3] Number of nucleus may be one or two.

Distribution: Present in the broadened part of the ureter, in the upper part of urinary bladder and urinary duct.

Function: [1] Defence, [2] Inhibit reabsorption of waste substances.

12. Write the distribution of different types of stratified epithelial tissue.

Ans. [1] Stratified squamous epithelium:

[a] Keratinised-hair, nail, horns, epidermis of skin. [b] Non-keratinised-Pharynx, oesophagus, vagina, mouth cavity.

[2] Stratified cuboidal epithelium: Sweat gland, conjunctiva.

[3] Stratified columnar epithelium: Glottis, epiglottis, rectum.

13. Write the characteristics, distribution and function of pseudostratified epithelium. 

Ans. Characteristics: [1] This tissue though is made up of single layered cells but the size of the cells are unequal hence it appears like stratified layer. [2] Cells may be ciliated or non-ciliated. [3] Nucleus of the cells lie at different plane.

Distribution: Present in large duct of salivary gland, urethra, etc.

Function: Protect associated organs and helps in movement of some substances.

14. What is meant by glandular epilhelium.

Ans. An epithelium, which has assumed a secretory function is termed as glandular epithelium. It is present in all types of exocrine and endocrine gland and is associated with the secretion of various secretory substances.

15. Write the distribution of sensory epithelinm.

Ans. Sensory epitheluim is found in nasal passages, taste buds.

16. Mention the distribution of muscular tissue.

Ans. [1] Voluntary muscles are attached to bones. [2] Smooth involuntary muscles are present in the vital visceral organs, such as oesophagus, intestine, urinary bladder, stomach etc. [3] Cardiac muscles are present in the heart..

17. Write down the functions of different types of muscles.

Ans. [1] Skeletal muscles help in movement and locomotion. [2] Smooth muscles control the movement of the visceral organs like stomach, intestine, urinary bladder, etc. [3] Cardiac muscles are responsible for rhythmic contraction and relaxation of the heart.

18. MOH What do you mean by voluntary or skeletal muscle? Write its functions. 

Ans. Muscles which are normally attached to the bones are called skeletal muscle.

Functions: [1] Contraction of these muscles is under the voluntary control (controlled willingly) of nervous system. Thus it help to maintain posture and stabilize bones and joints.

[2] Skeletal muscle associated with reflex action.

[3] These muscles can contract rapidly and are responsible for the quick movements and thereby coordinates the entire body.

19. Write the functions of unstriated muscles.

Ans. [1] Unstriated muscle fibres present around the blood vessels, help to maintain blood pressure. [2] Unstriated muscle fibre in digestive .tract help in the movement of food substances and thereby assist in digestion. [3] Presence of unstriated muscle in air passages regulate inflow and outflow of air. [4] In renal system unstriated muscle fibres propel the urine from kidney to urinary bladder.

20. What do you mean by intercalated disc. State its significance. 

Ans. Special fibrous discs are present at intervals of cardiac muscle is known as the Intercalated disc. >> They are transmitting the signals of nerve impulse between the cells of the heart.

21. Define haversian canal.

Or, Write its distribution.

Ans. Each osteon consists of a single central canal, known as a haversian canal, surrounded by concentric layers of calcified bone matrix. It allows the passage of blood vessels, lymphatic vessels and never fibres.

22. Name single nucleated and multinucleated muscle cell.

Ans. Single nucleated muscle cell is unstriated muscle cell, present in visceral organ.

Multinucleated muscle cell is striated muscle cell, present in hands and legs.

23. What is nervous tissue?

Ans. The tissue, which is responsible for receiving and transmitting impulses and thereby coordinating different parts of the body, is known as nervous tissue.

24. Which are the cellular components of nervous tissue? Where do you find those components? 

Ans. Cellular components of nervous tissue: Neurone and neuroglia are the two cellular components of the nerve tissue.

Distribution of neurone and neuroglia: Neurones are present in brain, spinal cord, sense organs and nerves. Several neurones, surrounded by connective tissue, form a nerve. Neuroglia cells are found in brain and spinal cord as packing material of neurones, providing them with necessary support and insulation.

25. Write the functions of nervous tissue.

Ans. [1] Nerve tissue receives external and internal stimuli and responds to them. [2] It carries impulses and makes the body aware of the changes in environment. [3] It helps to maintain coordination among all organs within the body.

Very Short Answer Type Questions

Multiple Choice Questions & Answers [MCQ]

1. Protection is the main function of-

A. Epithelial tissue

B. Muscular tissue

C. Nervous tissue

D. None of these

Ans. A

2. Histology is the study of-

A. Cells

B. Bones and muscles

C. Blood

D. Tissues

Ans. D

3. Rapid healing of wounds is found in-

A. Epithelial tissue

B. Muscular tissue

C. Connective tissue

D. Nervous tissue

Ans. A

4. The adjacent epithelial cells are held together by means of-

A. Microsomes

B. Liposomes

C. Glyoxysomes

D. Desmosomes

Ans. D

5. Inner lining of blood vessels are made up of-

A. Muscular tissue

B. Epithelial tissue

C. Connective tissue

D. None of these

Ans. D

6. Similarity between areolar and adipose tissue is-

A. Both provide protection

B. Both are connective tissues

C. Both help in coordination

D. All of these

Ans. B

7. The animal tissue which stores fat, is-

A. Blood

B. Areolar tissue

C. Muscle tissue

D. Adipose tissue

Ans. D

8. Camel’s hump is made up of-

A. Skeletal tissue

B. Muscular tissue

C. Cartilage

D. Adipose tissue

Ans. D

9. Animal body is structurally much more complex compared to that of plants, because-

A. Animals can move

B. Animals can feed on others

C. Animals have well-differentiated organs and organ systems

D. Animals can survive in air, earth and water

Ans. C

10 Embryonic connective tissue is derived from-

A. Ectoderm

B. Endoderm

C. Mesenchyma

D. Mesoglea

Ans. C

11. Which tissue is called the coordinating tissue?

A. Epithelial tissue

B. Muscle tissue

C. Nervous tissue

D. Blood

Ans. C

12. Which of the following is a conducting tissue?

A. Muscle tissue

B. Bone tissue

C. Adipose tissue

D. Blood

Ans. D

13. Which of the following tissues has no role in the protection of animal body?

A. Blood

B. Epithelial tissue

C. Nerve tissue

D. All of these

Ans. C

14. The walls of thick blood vessels are made up of-

A. Epithelial tissue and muscular tissue

B. Nervous tissue and epithelial tissue

C. Only muscular tissue

D. All of these

Ans. A

15. Which tissue acts as the shock absorber in our body?

A. Epithelial tissues

B. Bones

C. Muscles

D. Adipose tissues

Ans. D

Answer in a single word or sentence

1. Which tissue has liquid matrix?

Ans. Blood has liquid matrix.

2. Which tissue has rigid calcified matrix?

Ans. Bone tissue has rigid calcified matrix.

3. Where does connective tissue originate from?

Ans. Connective tissue originates from mesoderm.

4. Where does nervous tissue originate from? 

Ans. Nervous tissue originates from ectoderm.

5. Which tissue is responsible for absorption of nutrients from intestinal tract?

Ans. Epithelial tissue of intestinal lining is responsible for absorption of nutrients from intestinal tract.

6. Activity of which tissue or tissues directly controls the batting skill in the game of cricket?

Ans. Activity of muscular and nervous tissues controls the batting skill in the game of cricket.

7. Name a type of cell that is present in bones.

Ans. Osteocyte

8. Which tissue plays the major role in circulation of blood through blood vessels?

Ans. Muscular tissue, especially the cardiac muscles and muscular layer of blood vessels play major roles in circulation of blood through blood vessels.

9. Which proteins are responsible for muscular contraction?

Ans. Contractile proteins, viz.-actin and myosin

10. Which is the other name of voluntary muscle?

Ans. Skeletal muscle

11. Why voluntary muscles are called striated muscles?

Ans. Under microscope, alternate dark and light striations are seen across the voluntary muscle fibres. Therefore, these are called striated muscles.

12. Which type of cells is present on the inner lining of the respiratory tract?

Ans. Epithelial cells are seen on the inner lining of the respiratory tract.

13. Which type of muscles never get fatigued?

Ans. Cardiac muscles

14. Which tissue helps us to respond to the changes in the environment?

Ans. Nervous tissue

15. Which are the receiving projections of neurones?

Ans. Dendrons are the receiving projections of a neurone.

16. What are muscle fibres?

Ans. The fine elongated contractile components of muscular tissues are called muscle fibres. ..

17. Which type of muscles are branched?

Ans. Cardiac muscles are branched.

18. Which is the short and well-branched projection of a neurone?

Ans. Dendron is the short and well-branched projections of a neurone.

19. Name the longer and less branched projection of a nerve cell.

Ans. Axon is the longer and less branched projection of a nerve cell.

20. Name the lipid-rich insulating coating present on the axon.

Ans. The lipid-rich insulating coating present on the axon is known as myelin sheath.

21. Name the neurone, which does not have any lipid-rich insulating coating on the axon.

Ans. Non-myelinated neurone

22. Name the specialised nerve cells having lipidrich insulating coating on the axon.

Ans. The nerve cells, which have lipid-rich insulating coating on the axon, are called myelinated neurone.

23. Which is the most flexible connective tissue of our body?

Ans. Cartilage is the most flexible connective tissue of our body.

24. Which is the most rigid connective tissue of our body?

Ans. Bone is the most rigid connective tissue of our body.

25. Name the fluid connective tissues of human body.

Ans. Blood and lymph are the two fluid connective tissues of human body.

26. What type of tissue is tendon?

Ans. Tendon is a connective tissue.

27. Which two connective tissues are built for bearing weight of the body?

Ans. Bones and cartilages

Fill in the blanks

1. ……….. epithelium takes part in gaseous exchange.

Ans. Squamous

2 Epithelial layers receive nourishment from the underlying connective tissue through ………. membrane.

Ans. Basement

3. ………. tissue stores fat for future use.

Ans. Adipose

4. Blood and ……….. act as transporting fluids.

Ans. Lymph

5. Fluid connective tissue is ………..

Ans. Blood

6. Bone possesses a hard matrix composed of ……… and ………

Ans. Calcium, Phosphorus

7. Fibrous connective tissue is ………..

Ans. Collagen fibre

8. ………. is anchored to bones by tendons.

Ans. Muscle

9. Bones and ……… form the skeleton.

Ans. Cartilages

10. Haversian system is a diagnostic features of ………..

Ans. Bones

State True or False

1. Epithelial cells have a special role in secretion.

Ans. True

2. Epithelial tissue is also known as the contracting tissue.

Ans. False

3. Epithelial tissues are arranged on basement membrane.

Ans. True

4. Epithelial tissue helps in exchange of gaseous and liquid substances.

Ans. True

5. Amount of matrix is high in epithelial tissue.

Ans. False

6. Areolar tissue may not contain white and yellow fibre.

Ans. False

7. Fibrous tissues are a kind of epithelial tissue.

Ans. False

8. A skeletal muscle fibre is surrounded by a plasma membrane called sarcolemma.

Ans. True

TOPIC – 4

MAJOR ORGANS OF HUMAN BODY AND THEIR FUNCTION

SUMMARY

• A group of tissues having common origin and those having the same function is collectively called an organ.
• We have many organs like skin, stomach, pancreas, lungs, heart, spleen, kidney, liver, brain, spinal cord, testes, ovary, etc. Each of these perform different functions.
• Stomach is an organ of digestive system related to digestion of food stuff.
• Heart is an organ that deals with circulation of blood.
• Kidney is an organ which helps to excrete the waste products from our body.

Long Answer Type Questions

1. What is skin? Mention its distribution in human body and discuss its functions.

Ans. Skin

The skin is the outer covering of the human body and is considered as the largest organ. The skin consists of two layers [1] epidermis and [2] dermis.

Distribution of skin

The skin is spread throughout the body surface and guards the underlying muscles, bones, ligaments and internal organs.

Functions of skin

The functions of skin are as follows-[1] Skin protects our body from mechanical injuries. [2] Enzymes and salts, secreted through sweat, kill bacteria and other germs. [3] Sensory cells in skin help us to feel heat, touch, pressure, etc. [4] Skin absorbs sunrays to synthesise vitamin D for the body.

2. Mention the location of stomach in human body. Discuss its functions.

Ans. Location of human stomach

Stomach is situated on the left side of the upper abdomen, just below the muscular diaphragm.

Functions of stomach

The functions of human stomach are as follows-[1] Stomach is a large ‘J’ shaped sac-like structure that receives food from the oesophagus, stores it for some time and acts as a site of digestion of protein and fat. [2] HCl, secreted from the oxyntic cells of stomach, helps in activating the gastric enzymes. [3] Activated pepsin, present in gastric juice, acts upon proteins to break it into smaller derivatives, called peptones. [4] Lipase, present in gastric juice, helps in the hydrolysis of fat. [5] As the pH inside the stomach is acidic, microbes find it difficult to survive within it. Therefore, most microbes of the digestive flora remain within the gut and not in the stomach.

3. Mention the location of liver in human body. Discuss its functions.

Ans. Location of liver

Liver is present on the right ventral side of upper abdomen, just below the diaphragm.

Functions of liver

The functions of human liver are as follows-[1] Liver secretes bile, which neutralises the acidic contents of the stomach. [2] Bile salts emulsify fat and help in its digestion. [3] Liver primarily absorbs nutrients from blood before supplying it to different parts of the body. [4] It acts as the site of several metabolic activities. [5] Urea is synthesised within the liver. [6] Liver detoxifies various harmful components of the blood, like urea. [7] It helps in the synthesis of blood coagulating components like prothrombin, fibrinogen, etc.

4. Mention the location of pancreas in human body. State its functions.

Ans. Location of pancreas

Pancreas is an irregular, elongated gland situated in the abdominal cavity below the stomach, extending from duodenum to spleen.

Functions of pancreas

The functions of pancreas are as follows-[1] It secretes different digestive enzymes for the digestion of proteins, carbohydrates and fats. The enzymes are trypsin, amylase and lipase. [2] The pancreas produces essential hormones like insulin, glucagon and somatostatin in the body.

5. Mention the location of heart in human body. State its functions.

Ans. Location of heart

Heart is located in the thoracic cavity in between the two lungs. It remains slightly tilted towards the left.

Functions of heart

The functions of human heart are as follows-[1] Pumping of heart helps the blood to flow through blood vessels of the body. [2] It drives oxygenated blood from left ventricle through systemic circulation to different organs and tissues of the body. [3] Deoxygenated blood from right ventricle goes out to lungs through pulmonary circulation. [4] Heart receives deoxygenated and oxygenated blood into its right auricle and left auricle respectively.

6. Mention the location of kidney in human body. State its functions.

Ans. Location of kidney

Kidneys are held at the back wall of abdominal cavity on either sides of the vertebral column. Right kidney is positioned slightly lower than the left one.

Functions of kidneys

The functions of kidneys are as follows-[1] Formation of urine by filtration of blood. [2] Maintenance of water and electrolyte balance of our body. [3] Regulation of blood pressure by secretion of renin. [4] Control of formation of RBC by secretion of erythropoietin.

7. Mention the location of spleen in human body. Mention the functions of spleen.

Ans. Location of spleen

Spleen of human body is located on the upper far left side of the abdomen, below the left side of the stomach.

Functions of spleen

The functions of spleen are as follows-[1] In embryonic state, spleen acts as the site of RBC formation. [2] In adults, it produces lymphocytes (B-cells and T-cells) to help the proper functioning of immune system. [3] Spleen separates out and removes damaged, inactive and aged RBC from the blood stream: [4] It stores large quantity of RBC and leucocytes and releases them into the blood stream according to the need of the body.

8. What is ovary? Mention the position of human ovary and state its functions.

Ans. Ovary

The primary sex organ or gonad of female body is called ovary.

Location of ovary

Human ovaries are located at the two sides of lower abdominal cavity in females. Each ovary is an almond shaped structure, which is held in the abdominal wall with a thin membranous structure, a fibrous cord, known as the ovarian ligament.

Functions of ovary

The functions of human ovary are as follows-

Location of ovary [1] Several primordial germ cells are present in the ovary, which ultimately mature as ovum or female reproductive cells. [2] Ovary secretes hormones like oestrogen and progesterone. These two female hormones help to maintain the feminine features and reproductive cycle in female. [3] Hormone relaxin, secreted from the ovary, facilitates labour during childbirth.

Short Answer Type Questions

1. What is meant by organ?

Ans. An organised group of various specialised tissues which carry out a specific function of the body, is called an organ. Example-Heart, brain, etc.

2. What is a sebaceous gland? What is sweat?

Ans. Sebaceous gland: The gland present in the dermis layer of the skin, that secretes an oily substance called sebum, which keeps the skin smooth, is called the sebaceous gland.

Sweat: Sweat glands of skin produce aqueous fluid called sweat. It excretes water, NaCl, urea, amino acids, CO_₂, traces of lactic acid, etc.

3. Name the two layers of skin. Write the function of sweat.

Ans. The two layers of skin: [1] Epidermis and [2] Dermis.

Function of sweat: Excretion and cooling effect.

4. Define Melanocyte. State its function. 

Ans. Melanocyte: A cell in the skin and eyes that produces and contains the pigment called melanin. They are located in the layer of basal cells at the deepest part of the epidermis.

Functions: [1] Melanocyte produces a pigment called Melanin. [2] Melanin provides protection against UV-induced DNA damage by absorbing and scattering UV-radiation.

5. Why does your skin change colour in the sun?

Ans. Exposure to the ultraviolet radiation from the sun causes changes to the skin colour. It occurs not because of increased melanin production but due to redistribution of melanin stored in keratinocytes in the upper layers of the skin.

6. Why bleeding does not occur due to cut or e to cut o scrape on epidermis of the skin?

Ans. There are no blood vessels in epidermis. Due to this reason, bleeding does not occur even if the epidermis is cut or scraped.

7. Mention the location and function of peptic cell.

Ans. Peptic cell is located at the mucous layer of stomach. It is also known as chief cell.

Function: It secretes a substance called pepsinogen which gives rise to pepsin, an enzyme that helps in digestion of protein.

8. Mention the location and function of oxyntic or parietal cell.

Ans. In the stomach, the mucous layer contains oxyntic or parietal cells that secretes HCl.

Function: [1] Parietal cells secrete HCl and Intrinsic factor. [2] HCl helps pepsin to digest protein upto peptone. [3] HCl hydrolyses foods in the stomach. [4] HCI kills bacteria and other germs engulfed with foods. [5] Intrinsic factor helps in absorption of Vitamin B₁₂.

9. What do you mean by gastric glands? What are its function? 

Ans. Gastric glands: There are numerous microscopic tubular glands, found in the epithelium of stomach. There are three types of cells which are as follows-[1] Peptic cells or Chief cells, [2] Parietal cells or Oxyntic cells. [3] Mucous cells or Goblet cells.

Function: The gastric juice secreted by the gastric glands of stomach helps in protein metabolism.

10. What is pleura? Write its function.

Ans. Pleura: The lungs are surrounded by a thin transparent double layered membrane called pleura.

Function: [1] Pleura protects the lungs from mechanical injury. [2] It helps in the free movement of the lungs.

11. What is alveoli? State its function.

Ans. Alveoli: Alveoli are balloon-shaped air sacs present at the very end of the respiratory tree and are arranged in clusters throughout the lungs.

Function: The function of alveoli is to exchange oxygen and carbon dioxide molecules to and from the blood stream.

12. What is mixed gland?

Ans. They have both an exocrine and an endocrine part. The exocrine part secretes juices with enzymes which come out through the duct. The endocrine part secretes hormone which is carried directly by blood or body fluids. ExamplesPancreas, testis.

13. Name two enzymes and two hormones and two hon secreted by pancreas.

Ans. Trypsin and chymotrypsin are the enzymes released by pancreas. Insulin and glucagon are two hormones secreted from endocrine part of pancreas.

14. Mention the location and functions of human lungs.

Ans. Location: The two lungs re situated at the two sides of chest cavity within the rib cage.

Functions: [1] Lungs help in the intake of O₂-rich air by inspiration and expulsion of CO₂-rich air by expiration. [2] Lungs also help in the excretion of few other toxic materials by expiration.

15. Name a hormone and the major enzyme secreted by the stomach.

Ans. Gastrin is a hormone secreted by the stomach and pepsin is the major enzyme secreted by the stomach.

16. Name the two major blood vessels of the kidney and name the protective layer of kidney.

Ans. The two major blood vessels of the kidney are the renal vein and renal artery and the protective layer of kidney is called capsule.

Very Short Answer Type Questions

Multiple Choice Questions & Answers [MCQ]

1. Which is the largest organ of our body?

A. Liver

B. Intestine

C. Skin

D. Brain

Ans. C

2. Select the correct statement-

A. An organ is an assemblage of many tissues

B. An organ is an assemblage of different tissues, performing a specific function of the body

C. Any part of the body is called organ

D. An organ is a body part present inside the body

Ans. B

3. The protective layer of human body that prevents the attack of different germs is-

A. Composed of epithelium

B. Composed of connective tissue

C. Skin

D. Dermis

Ans. C

4. The largest lymph gland in animal body, is—

A. Spleen

B. Liver

C. Pancreas

D. Stomach

Ans. A

5. The organ of human body responsible for partial digestion is-

A. Liver

B. Stomach

C. Small intestine

D. Pancreas

Ans. B

6. The organ of human body secreting HCl is-

A. Liver

B. Pancreas

C. Stomach

D. Kidney

Ans. C

7. The food matters inside the stomach become-

A. Acidic

B. Basic

C. Neutral

D. Slightly alkaline

Ans. A

8. Pepsinogen is converted into pepsin within the-

A. Liver

B. Duodenum

C. Stomach

D. Large intestine

Ans. C

9. The organ that produces a number of enzymes and hormones is-

A. Heart

B. Liver

C. Brain

D. Pancreas

Ans. D

10. The organs involved in secretion of pepsin and trypsin are-

A. Liver and pancreas

B. Gastric glands and pancreas

C. Liver and stomach

D. Salivary gland and gall bladder

Ans. B

11. The organ of human body, where digestion of protein starts is-

A. Stomach

B. Duodenum

C. Jejunum

D. Buccal cavity

Ans. A

12. Bile, secreted from the liver is-

A. Alkaline

B. Acidic

C. Slightly acidic

D. Neutral

Ans. A

13. The organ of human body involved in detoxification is-

A. Stomach

B. Liver

C. Pancreas

D. Spleen

Ans. B

14. Formation of urea is the function of-

A. Liver

B. Kidney

C. Stomach

D. Small intestine

Ans. A

15. The diaphragm is located below the-

A. Kidneys

B. Stomach

C. Lungs

D. Spleen

Ans. C

16. The organ, helping in neutralisation of the acidic contents of the stomach is-

A. Duodenum

B. Liver

C. Pancreas

D. Jejunum

Ans. C

17. The organ responsible for absorption of fat is-

A. Stomach

B. Kidney

C. Pancreas

D. Liver

Ans. D

18. …….. of human body acts as the ‘Graveyard of RBC’.

A. Lung

B. Kidney

C. Spleen

D. Rectum

Ans. C

19. Different plasma proteins are synthesised in-

A. Kidney

B. Liver

C. Spleen

D. Heart

Ans. B

20. Immunity of our body is controlled by-

A. Stomach

B. Heart

C. Spleen

D. Brain

Ans. C

Answer in a single word or sentence

1. Which two layers constitute our skin?

Ans. Epidermis and hypodermis constitute our skin.

2. Which is the largest sense organ of our body?

Ans. Skin is the largest sense organ of our body.

3. Which organ of our body carries the sensory cells for perception of heat and pressure?

Ans. Skin

4. Mention the two functions of skin. 

Ans. Two functions of skin are-[1] Skin helps in excretion and water regulation. [2] It also helps in regulation of body temperature.

5. Which organ of our body can store the food for some time during digestion?

Ans. Stomach

6. Which organ of the human digestive system acts as the killing field for most of the microbes, taken with food?

Ans. Stomach

7. Besides killing germs within the consumed food, what other function does HCl do inside stomach?

Ans. Besides killing germs within the consumed food, HCl activates pepsinogen into pepsin inside the stomach.

8. Name a highly extensible sac-like structure located at the left side of the upper abdomen.

Ans. Stomach

9. The lumen of which organ always remains in acidic state?

Ans. The lumen of stomach always remains in acidic state.

10. Name the organ of human body which helps in neutralising the acidic food mass, coming into duodenum from the stomach.

Ans. Liver secretes bile, which neutralises the acidic food mass, coming into duodenum from the stomach.

11. The proteolytic enzyme, pepsin is secreted by which cell of stomach?

Ans. Peptic or chief cell of stomach secretes pepsin in an inactive form called pepsinogen.

12. Which organ is located just below the stomach at the left side of the abdomen?

Ans. Spleen

13. Name the local hormone secreted by stomach.

Ans. Gastrin

14. Name the enzyme secreted by the stomach.

Ans. Pepsin

15. Name the largest gland of human body which is composed of densely packed tissues.

Ans. Liver

16. Name the largest digestive gland of our body.

Ans. Liver

17. Name one mixed gland.

Ans. Pancreas

18. From which digestive gland trypsin is secreted? 

Ans. Pancreas

19. Insulin hormone is secreted from which gland?

Ans. Pancreas

20. Which digestive juice neutralises the HCl secreted by stomach?

Ans. Pancreatic juice

21. Name the largest lymphoid gland of human body.

Ans. Spleen

22. Which organ removes dead RBCs from blood?

Ans. Spleen removes dead RBCs from the blood.

23. Name one gland in human body that secretes digestive enzymes along with hormones.

Ans. Pancreas

24. Which two organs of our body contract and expand continuously throughout our lives?

Ans. Heart and lungs

25. Name the paired organs which are protected by rib bones from all sides.

Ans. The lungs are the paired organs which are protected by rib bones from all sides.

26. Name the outer membrane of lungs.

Ans. Pleura

27. Name the organ of our body, through which blood passes along two different paths.

Ans. Heart is the organ of our body, through which blood passes along two different paths.

28. What do you mean by pericardium?

Ans. The heart remains surrounded by a double layered transparent sac called pericardium. It protects the heart from mechanical friction with the adjoining structures.

29. Which organ of our body remains protected in a roundish bony case known as cranium?

Ans. Brain

30. Which organ transmits messages in form of impulses?

Ans. Brain

31. This elongated cord-like structure acts as the centre for reflex action of our body. What is it?

Ans. Spinal cord

32. Name the cells from which testosterone is secreted inside the testes of male.

Ans. Leydig cells

33. Name two hormones secreted by the corpus luteum in females.

Ans. Oestrogen and progesterone

34. What is the process of production of ovum called?

Ans. Oogenesis

35. Name two hormones influencing secretion of oestrogen.

Ans. FSH (Follicle Stimulating Hormone) and LH (Luteinizing Hormone)

36. Which paired structures keep our blood clean from metabolic wastes?

Ans. The kidneys keep our blood clean from metabolic wastes.

37. In which organ ammonia is converted to urea?

Ans. Liver

38. Name the chief excretory product of human.

Ans. Urea

39. Renin and erythropoietin are released from which organ?

Ans. Kidney

Fill in the blanks

1. ………. is the membrane, lining the cavity of abdomen and covering the abdominal organs.

Ans. Peritoneum

2. Stomach helps in partial digestion of protein, by secreting ……….

Ans. Pepsin

3. Contraction of heart is known as ………..

Ans. Systole

4. There are ……….. chambers in human heart.

Ans. Four

5. Toxic wastes of human body are filtered out by …………

Ans. Kidney

6. The main organ of circulatory system is …………

Ans. Heart

7. ……….. is the protective covering of human brain.

Ans. Cranium

8. The process of production of spermatozoa is known as ……….

Ans. Spermatogenesis

9. ………. is the outer covering of the human body.

Ans. Skin

10. ………. contain lysozyme to destroy bacterial cell wall. 

Ans. Tears

11. HCl is secreted by the ……….. cell of stomach.

Ans. Oxyntic or parietal

12. ……….. are located in the thoracic cavity above the diaphragm.

Ans. Lungs

13. Structural unit of lungs is ………….

Ans. Alveoli

14. Thoracic cage is made up of 12 pairs of …………

Ans. Ribs

15. …………. is situated in the left hypochondrium directly beneath the diaphragm.

Ans. Spleen

16 ……….. engulf bacteria and foreign particles in blood.

Ans. Spleen

17. Kidney is situated below the membrane called ………. membrane.

Ans. Peritoneum

18. Bile is stored in ………….

Ans. Gall bladder

19. …………. produces ovum.

Ans. Ovary

State True or False

1. Sweat helps to kill bacteria.

Ans. True

2. The pigment which gives colour to the skin is melatonin.

Ans. False

3. Skin involved in synthesis of vitamin D.

Ans. True

4. Liver secretes bile.

Ans. True

5. Spleen is an organ, where formation and destruction of RBC occurs.

Ans. True

6. Spleen controls metabolism of carbohydrates, proteins and fats. 

Ans. False

7. All emotions are the sensory informations towards the brain.

Ans. False

8. Only brain makes central nervous system.

Ans. False

9. Human heart drives oxygenated blood from left ventricle to the body, through pulmonary circulation.

Ans. False

10. Heart is an organ of the circulatory system.

Ans. True

11. Kidney is held at the back wall of abdominal cavity.

Ans. True

12. Kidney is a rod shaped structure.

Ans. False

13. The functional unit of kidney is neurone.

Ans. False

14. Urea is produced in the kidneys.

Ans. False

15. Diaphragm is present between thoracic and abdominal cavity.

Ans. True