P S VERMA AND V K AGARWAL Solutions for Class 9 Biology Chapter 3 - Tissues

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Chapter 3 - Tissues Exercise 165

Question 1

What is the importance of tissues?

Solution 1

Importance of tissues-

(i) Formations of tissues have brought about a division of labour in multicellular organisms.

(ii) Tissues become organised to form organs and organs organise into organ system.

Question 2

Why do plant and animals possess different types of tissues?

Solution 2

Plants are autotrophic organisms, so prepare their own food by photosynthesis. Moreover plants are stationary or fixed organisms; they do not have to move from place to place in the search of their food. Since they do not consume or need much energy, so most of the plant tissues are supportive, which provide them with structural strength. Animals are heterotrophic organisms. They have to move in search of food, mate and find shelter, so they need more energy as compared to plants. Most of the tissues they contain are living.

Question 3

Tabulate differences between plants and animal tissues.

Solution 3

Plant Tissues

Animal Tissues

1. They require less maintenance energy.

2. There is a differentiation of meristematic and permanent tissues.

1. They require more maintenance energy.

2. Such a differentiation is absent in them.

Question 4

Write a short note on intercalary meristem.

Solution 4

They are located at the base of leaves or internodes, e.g., stems of grasses and other monocots. Such tissues also occur below the nodes. It produces an increase in the length of an organ such as leaves and internodes.

Question 5
Write one main function of

(a) Apical meristem

(b) Lateral meristem.
Solution 5

(i) Apical meristem - It brings about the elongation of the root and stem.

(ii) Lateral meristem - It causes the organ (stem or root) to increase in diameter and girth.

Question 6

What are simple tissues? Explain their three different types.

Solution 6

Simple permanent tissues - These tissues are composed of cells which are structurally and functionally similar.

There are three types of simple permanent tissues:

(i) Parenchyma - Parenchyma cells are living and posses the power of division. The cell wall is thin and encloses a dense cytoplasm which contains a small nucleus and surrounds a large central vacuole.

(ii) Collenchyma - Its tissues consists of living cells. It is characterized by the deposition of extra cellulose at the corners of the cells. In collenchymas, intercellular spaces are generally absent. Collenchyma cells are elongated in shape. They often contain a few chloroplasts.

(iii)Sclerenchyma - Sclerenchyma cells are dead cells and they are devoid of protoplasm. The cells walls of Sclerenchyma are greatly thickened of lignin. The cells of Sclerenchyma are closely packed without intercellular spaces.

Chapter 3 - Tissues Exercise 166

Question SAQ - 1

Explain different types of elements present in phloem.

Solution SAQ - 1

The different types of elements present in the phloem are:

(i) Sieve tubes - Sieve tubes are slender, tube-like structures composed of elongated thin-walled cells, placed end to end. Their end walls are perforated by numerous pores and are called sieve plates.

(ii) Companion Cells - It is a small thin-walled cell containing dense and very active cytoplasm and large elongated nucleus.

(iii) Phloem parenchyma - These are thin-walled, living cells of parenchyma of phloem. They have two functions, storage and slow lateral conduction of food.

(iv) Phloem Fibre - These are thick-walled, elongated spindled shaped dead cells which posses narrow lumen. They provide mechanical strength to the tissue.

Question SAQ - 2

What are tracheary elements? Describe their functions.

Solution SAQ - 2

Tracheary elements are the elements of xylem. Their function is to carry water and mineral salts in upward direction from the roots to different part of shoots.

Question SAQ - 3

Write the functions of parenchyma, collencyma and sclerenchyma.

Solution SAQ - 3

(i) Parenchyma Functions:


(a) The main function of parenchyma is to store and assimilate food.

(b) Transport of materials occurs through cells or cell walls of parenchyma cells.


(ii) Collenchyma Functions:

(a) It provides mechanical support and elasticity.

(b) It provides tensile strength to the plants.


(iii) Sclerenchyma Functions:

(a) It is mainly mechanical and protective in function.

(b) It gives strength, rigidity, flexibility and elasticity to the plant body.

Question SAQ - 4

What is the difference between parenchyma and collenchymas?

Solution SAQ - 4
Parenchyma Collenchyma
1. The tissue consists of thin-walled living cells.

2. It is distributed in almost all the parts of the plant body.

3. The living cells of parenchyma assimilate and store food. They also store waste products.
1. The tissue consists of cells having localised thickening in their cell walls.

2. It occurs mostly in the aerial parts of the plants and is restricted to the other layers.

3. Collenchyma is the chief mechanical tissue in parts of a young plant particularly in the young dicotyledonous stems.
Question SAQ - 5
What jis the difference between collenchyma and sclerenchyma?
Solution SAQ - 5

Collenchyma

Sclerenchyma

1. It consists of living cells.

2. Its cells contain cytoplasm.

3. Its cell walls are cellulosic.

1. It consists of dead cells.

2. Its cells are empty.

3. Its cell walls are lignified.

 

Question SAQ - 6

Name the different types of elements found in the xylem.

Solution SAQ - 6

Xylem is composed of cells of four different types: 1. Tracheids; 2. Vessels or tracheae; 3. Xylem parenchyma and 4. Xylem Sclerenchyma. Except xylem parenchyma, all other xylem elements are dead and bounded by thick lignified walls. Vessels are shorter and wider than tracheids. Vessels are very long tube-like structures formed by a row of cells placed end to end. Tracheids are elongated cells with tapering ends. They also conduct water.

Question SAQ - 7

What are the functions of xylem?

Solution SAQ - 7

Functions of Xylem:

(i) The main function of xylem is to carry water and mineral salts upward from the root to different parts of shoots.

(ii) Since walls of tracheids, vessels and sclerenchyma of xylem are lignified, they give mechanical strength to the plant body.

Question SAQ - 8

What are the functions of phloem?

Solution SAQ - 8

Functions of Phloem:

Phloem transports photosynthetically prepared food materials from the leaves to the storage organs and later from storage organs to the growing regions of the plant body.

Question SAQ - 9

Write down names of different types of plant tissues.

Solution SAQ - 9

The different types of plant tissues are:

1. Meristematic tissues - It is of three types: Apical, Lateral and Intercalary.

2. Permanent Tissue - It of two types: Simple and Complex tissues. Simple tissues are of three types - Parenchyma, Collenchyma and Sclerenchyma.

Complex tissues are of two types - Xylem and Phloem.

Question SAQ - 10

Explain how sieve tubes manage to be living?

Solution SAQ - 10

Sieve tube elements do not have nuclei but have cytoplasm. They are dependent on adjacent companion cells which contains dense and very active cytoplasm and a large elongated nucleus.

Question SAQ - 11

Give four important functions of epithelial tissue. Name one specific place in the body where each function is carried out.

Solution SAQ - 11

Functions of Epithelial tissues are:

(i) The cells of the body surface form the outer layer of skin. These cells protect the underlying cells from drying, injury, and chemical effects.

(ii) Inside the body, epithelial cells form lining of mouth and alimentary canal and protect these organs.

(iii) Epithelial tissues help in absorption of water and nutrients in small intestine.

(iv) Some epithelial tissues perform secretory function such as sweat, saliva in skin and mouth cavity.

Question SAQ - 12

Enlist three types of muscles with their locations.

Solution SAQ - 12

(i) Striated Muscles - It occur in the muscles of limbs, body wall, face, neck, etc. Striated muscles present in tongue, pharynx, diaphragm and upper part of oesophagus are called visceral straited muscles.

(ii) Smooth Muscles - Smooth muscles are found in the walls of the hollow (tubular) visceral organs except that of the heart. They occur in the wall of alimentary canal and internal organs, ducts of glands, urogenital ducts and blood vessels.

(iii) Cardiac Muscles - The cardiac muscles occur in the heart.

Question SAQ - 13

In which tissue is found anyone of the following structures: neuron, dendrite, cilia, collagen fibres, elastion fibre.

Solution SAQ - 13

(a) Neuron - Nervous Tissue

(b) Dendrite - Nervous Tissue

(c) Cilia - Ciliated Epithelium

(d) Collagen fibres - Connective Tissue

(e) Elastin fibre - Connective Tissue

Question SAQ - 14

List one function for each of following : osteoblast, chondroblast, goblet cell, neuron, muscle cell.

Solution SAQ - 14

(a) Osteoblast - It provides shape to the body.

(b) Chondroblast - It provided support and flexibility to the body parts.

(c) Goblet Cells - It is a mucus secreting epithelial cell which secrets mucus.

(d) Neuron - The dendrites receive impulses and the axon takes impulses away from the cell body.

(e) Muscle Cell - They undergo rapid contraction for locomotion.

Question SAQ - 15

State two characteristics of nerve cells.

Solution SAQ - 15

Two characteristics of nerve cells are:

(i) They are highly specialised unit cells.

(ii) Neurons have the ability to receive stimuli from within or outside the body and to conduct (send) impulses (signals) to different parts of the body.

Question SAQ - 16

What is the function of bone, cartilage and ligament?

Solution SAQ - 16

Bone - It provides skeletal support to the body.

Cartilage - It provides support and flexibility to the body parts.

Ligament - It connects bones to bones.

Question SAQ - 17
Name the following:

(a) Tissue which stores fat.

(b) Epithelium which lines lung alveoli.
Solution SAQ - 17

(a) Adipose tissues.

(b) Ciliated epithelium.

Question SAQ - 18

Given three functions of blood.

Solution SAQ - 18

Functions:

(i) It transports nutrients, hormones and vitamins to the tissues and transports excretory products from the tissues to the liver and kidney.

(ii) The RBCs carry oxygen to the tissues for the oxidation of food stuff.

(iii) WBCs fight disease by engulfing and destroying foreign bodies.

Question SAQ - 19

What are the different tissues in animals.

Solution SAQ - 19

The different tissues in animals are:

(i) Epithelial Tissues - These are the protective tissues of the animal body. Depending upon the shape and function of the cells, the epithelial tissues are classified as follows:

a. Squamous epithelium.

b. Cuboidal epithelium.

c. Columnar epithelium.

d. Glandular epithelium.

e. Ciliated epithelium.


(ii) Muscular Tissues - The muscular tissues form the contractile tissues and are made up of muscle cells. On the basis of their location, structure and function, there are three types of muscular tissues:

a. Striated muscles.

b. Smooth muscles.

c. Cardiac muscles.


(iii) Connective Tissues - The connective tissues are specialised to connect and anchor various body organs. They are of five types:

a. Aerolar connective tissue.

b. Dense regular connective tissue.

c. Adipose tissues.

d. Skeletal tissues.

e. Fluid connective tissues.


(iv) Nervous Tissues - These tissues are specialised to transmit messages within our body. Brain, spinal cord and nerves are all composed of nervous tissues.

Question SAQ - 20

Draw and lable a neuron.

Solution SAQ - 20

P-s-verma-and-v-k-agarwal Solutions Cbse Class 9 Biology Chapter - Tissues

Question SAQ - 21

Diagrammatically show the difference in three types of muscle fibres.

Solution SAQ - 21
P-s-verma-and-v-k-agarwal Solutions Cbse Class 9 Biology Chapter - Tissues
Question LAQ - 1

What are different types of tissues in plant?

Describe simple tissues.

Solution LAQ - 1

P-s-verma-and-v-k-agarwal Solutions Cbse Class 9 Biology Chapter - Tissues 

Simple tissues - These tissues are composed of cells which are structurally and functionally similar.

There are three types of simple tissues:

(i) Parenchyma - Parenchyma cells are living and posses the power of division. The cell wall is thin and encloses a dense cytoplasm which contains a small nucleus and surrounds a large central vacuole.

(ii) Collenchyma - It tissues also consists of living cells. It is characterized by the deposition of extra cellulose at the corners of the cells. In collenchymas, intercellular spaces are generally absent. Collenchyma cells are elongated in shape. They often contain a few chloroplasts.

(iii) Sclerenchyma - Sclerenchyma cells are dead cells and they are devoid of protoplasm. The cells walls of Sclerenchyma are greatly thickened by the deposition of lignin. The cells of sclerenchyma are closely packed without intercellular spaces.

Question LAQ - 2

What are meristematic tissues? Explain with the help of suitable diagram. Give their classification on the basis of their position in the plant body.

Solution LAQ - 2

 Meristematic tissues are the tissues in which the cells divide continuously and help in increasing the length and girth of the plant.

                                    

                                                   P-s-verma-and-v-k-agarwal Solutions Cbse Class 9 Biology Chapter - Tissues

According to their position in the plant, meristems are of three types:

a) Apical Meristems - These are situated at the growing tip of the stems and roots and increase the height of the plant.

b) Lateral Meristems - These are found beneath the bark and in vascular bundles of dicot roots and stems. These are responsible for the growth of cambium and hence increases the girth of the plant.

c) Intercalary Meristems - They are located at the base of leaves or internodes or below the nodes. It increases the length of the plant.

P-s-verma-and-v-k-agarwal Solutions Cbse Class 9 Biology Chapter - Tissues

Question LAQ - 3

What is simple tissue? Classify and explain its different types with suitable diagram.

Solution LAQ - 3

Simple tissues - These tissues are composed of cells which are structurally and functionally similar.

There are three types of simple tissues:

(i) Parenchyma - Parenchyma cells are living and posses the power of division. The cell wall is thin and encloses a dense cytoplasm which contains a small nucleus and surrounds a large central vacuole.

P-s-verma-and-v-k-agarwal Solutions Cbse Class 9 Biology Chapter - Tissues

(ii) Collenchyma - It tissues also consists of living cells. It is characterized by the deposition of extra cellulose at the corners of the cells. In collenchymas, intercellular spaces are generally absent. Collenchyma cells are elongated in shape. They often contain a few chloroplasts.

P-s-verma-and-v-k-agarwal Solutions Cbse Class 9 Biology Chapter - Tissues

(iii) Sclerenchyma - Sclerenchyma cells are dead cells and they are devoid of protoplasm. The cells walls of sclerenchyma are greatly thickened by the deposition of lignin. The cells of sclerenchyma are closely packed without intercellular spaces.

P-s-verma-and-v-k-agarwal Solutions Cbse Class 9 Biology Chapter - Tissues

Question LAQ - 4
What do you know about complex tissue? Classify and explain its different types in plants with suitable diagrams.
Solution LAQ - 4
The complex tissue consists of more than one type of cells having a common origin. They are of two types:

(a) Xylem - Xylem is a vascular and mechanical tissue which conducts water. Xylem is composed of cells of four different types: 1. Tracheids; 2. Vessels or tracheae; 3. Xylem parenchyma and 4. Xylem Sclerenchyma. Except xylem parenchyma, all other xylem elements are dead and bounded by thick lignified walls. Vessels are shorter and wider than tracheids. Vessels are very long tube-like structures formed by a row of cells placed end to end. Tracheids are elongated cells with tapering ends. They also conduct water.

P-s-verma-and-v-k-agarwal Solutions Cbse Class 9 Biology Chapter - Tissues

 

(b) Phloem - Phloem is also a vascular tissue which transports food from the leaves to the various parts of the plant. It is composed of:

(i) Sieve tubes - Sieve tubes are slender, tube-like structures composed of elongated thin-walled cells, placed end to end. Their end walls are perforated by numerous pores and are called sieve plates.

(ii) Companion Cells - It is a small thin-walled cell containing dense and very active cytoplasm and large elongated nucleus.

(iii) Phloem parenchyma - These are thin-walled, living cells of parenchyma of phloem. They have two functions, storage and slow lateral conduction of food.

(iv) Phloem Fibres - These are thick-walled, elongated spindled shaped dead cells which posses narrow lumen. They provide mechanical strength to the tissue.

P-s-verma-and-v-k-agarwal Solutions Cbse Class 9 Biology Chapter - Tissues

Question LAQ - 5
Distinguish between the following pairs in one or two sentences for each

(a) RBCs and WBCs;

(b) bone and cartilage;

(c) blood and lymph;

(d) striated and unstriated muscles;

(e) tendon and ligament;

(f) axon and dedrite.
Solution LAQ - 5

(a)

RBC's

WBC's

(i) They are red in colour.

(ii) Nucleus is absent.

(i) They are colourless.

(ii) Nucleus is present.

(b)

Bone

Cartilage

(i) It is hard and inflexible.

(ii) Blood vessels are present.

(i) It is soft and flexible.

(ii) Blood vessels are absent.

(c)

Blood

Lymph

(i) Blood is red in colour.

(ii) RBC's are present.

(i) Lymph is a colourless fluid.

(ii) It's composition is almost similar to blood except RBC's are absent.

(d)

Striated Muscles

Unstriated Muscles

(i) They are long and cylindrical in shape.

(ii) These muscles show alternate light and dark bands or striations.

(i) These are spindle shaped.

(ii) These muscles do not show striations.

(e)

Tendon

Ligament

(i) It is inelastic in nature.

(ii) It joins muscles to bones.

(i) It is elastic in nature.

(ii) It joins bones to bones.

(f)

Axon

Dendrite

(i) It is a long uniformly thickened fibre like process of a neuron.

(ii) It carried impulses away from the cell body.

(i) It is a short tapering process of the neuron.

(ii) It carries impulses towards the cell body.

 

Question LAQ - 6

Describe the structure and functions of epithelium.

Solution LAQ - 6

Epithelium is the simplest tissue. It is the protective tissue of the animal body in which the cells are tightly packed having no intercellular matrix. Epithelial cells lie on a delicate non-cellular basement membrane which contains a special form of matrix protein, called collagen. These tissues perform the function of excretion, secretion and absorption. Depending upon the shape and functions of the cells, the epithelial tissue is of various types -

(i) Squamous - The cells are flat and polygonal and are arranged as tiles. These tissues occur in skin, lining of alveoli of lungs, blood vessels etc. Its function includes protection, diffusion and osmosis.

(ii) Cuboidal - The cells are cube like. These occur in glands, germinal layer of ovary, kidney tubules etc. Its function is secretion and absorption.

(iii) Columnar - The cells are pillar or column like resting on a thin membrane. Such tissues occur in the lining of stomach, intestine etc. Its function includes protection, absorption and secretion.

(iv) Ciliated - It has cuboidal, columnar cells with fine hair like structures called cilia. It is present in the lining of respiratory tract, fallopian tube, nephron etc. Its function is protection, spreading of mucus and motion of gases and liquids by cilia.

(v) Glandular - The cells are cubical. These can be branched or unbranched. Such tissues are present in glands. Its main function is secretion.

Question LAQ - 7

Classify connective tissue and give one example of each type.

Solution LAQ - 7

The connective tissue is specialized to connect and anchor various body organs. There are five types of connective tissues:

(i) Areolar: This tissue is a loose and cellular connective tissue. Its matrix consists of white collagen fibre and yellow elastic fibre. It joins skin to muscles, fills spaces inside organs and is found around muscles, blood vessels and nerves.

(ii) Dense Regular Connective tissue: It is fibrous connective tissue having densely packed fibres and cells. It is the principal component of tendons, ligaments and aponeuroses.

(iii) Adipose tissue: It is an aggregation of fat cells or adipocytes. The fat cells are arranged into lobules separated by partitions of collagen and elastin fibres. These are found abundant below the skin, between the internal organs and in yellow bone marrow.

(iv) Skeletal tissue: It is a supporting tissue which includes cartilage and bone. Both these tissues form the endoskeleton of a vertebrate body. Cartilage is located in ear pinna, nose tip, epiglottis etc. Bone forms the endoskeleton in human beings and provides shape to the body.

(v) Fluid tissue: It links the different parts of the body and maintains continuity in the body. It includes blood and lymph.

Question LAQ - 8

Describe the composition and functions of blood.

Solution LAQ - 8

Blood is a fluid connective tissue. There are three types of blood corpuscles:

(i) RBC's or Erythrocytes - These are bi-concave, denucleated, disc like. They contain red coloured respiratory pigment called haemoglobin that helps in the transportation of oxygen.

(ii) WBC's or leucocytes - These are irregular, amoeboid, phagocytic cells with one to many lobed nucleus. These cells protect the body against the diseases by producing antibodies.

(iii) Blood platelets or thrombocytes - These are spindle shaped cells which help in the clotting of blood.

Functions of blood:

(i) It transports nutrients, hormones and vitamins to the tissues and transports excretory products from the tissues to the liver and kidney.

(ii) The RBCs carry oxygen to the tissues for the oxidation of food stuff.

(iii) WBCs fight disease by engulfing and destroying foreign bodies.

Question LAQ - 9

Define muscular tissue. Classify and explain different types of muscles with the help of suitable diagrams.

Solution LAQ - 9

Muscular tissues form the muscles in the body and are responsible for movement and locomotion. Muscle cells are elongated and are called muscle fibres. They are capable of contraction and relaxation. There are three types of muscular tissues:

(i) Striated Muscles or Skeletal muscles - These are called skeletal muscles as they are found attached to the bones and help in the body movements. The cells are cylindrical, unbranched, striated and multi nucleated. They are involuntary in nature.

(ii) Non-Striated muscles or smooth muscles - The cells are spindle shaped, uni-nucleated, elongated and have no striations. They are found within the walls of elementary canal, bladder and blood vessels. They are involuntary in nature.

(iii) Cardiac Muscles - These are found exclusively in heart. They are cylindrical, non-tapering, branched with faint striations. They have one or two nuclei in each cell. They are involuntary. Their function is rhythmic contraction and relaxation throughout life.

 

P-s-verma-and-v-k-agarwal Solutions Cbse Class 9 Biology Chapter - Tissues
Question LAQ - 10

Explain the structure of neuron with the help of a labeled diagram.

Solution LAQ - 10

The neuron consists of three parts:

(i) The Cyton or Cell body - It contains a central nucleus and cytoplasm with deeply stained particles called Nissl's granules.

(ii) Dendrites - The dendrons are short processes arising from the cyton and branches into dendrites.

(iii) Axon - It is a single, long cylindrical process which forms fine branches terminally. It has a swollen structure at its end called synaptic knob or bouton. It is also termed as the nerve fibre.

P-s-verma-and-v-k-agarwal Solutions Cbse Class 9 Biology Chapter - Tissues

Question 7
Draw a well labelled diagram of parenchyma and collenchyma.
Solution 7
(a) Parenchyma

P-s-verma-and-v-k-agarwal Solutions Cbse Class 9 Biology Chapter - Tissues

(b) Collenchyma

P-s-verma-and-v-k-agarwal Solutions Cbse Class 9 Biology Chapter - Tissues
Question 8

Draw a well labeled diagram of phloem.

Solution 8
P-s-verma-and-v-k-agarwal Solutions Cbse Class 9 Biology Chapter - Tissues

                                     Phloem Tissue
Question 9

Draw a well labeled diagram of xylem.

Solution 9
Xylem Tissue

P-s-verma-and-v-k-agarwal Solutions Cbse Class 9 Biology Chapter - Tissues
Question 10

Give two functions of collenchymas.

Solution 10

Functions of Collenchyma:

(i) It provides mechanical support and elasticity.

(ii) It provides tensile strength to the plants.

Question 11

Write a short note on sclerenchyma.

Solution 11

Sclerenchyma cells are dead cells and they are devoid of protoplasm. The cells walls of sclerenchyma are greatly thickened by lignin. The cells of sclerenchyma are closely packed without intercellular spaces.

Question 12

Distinguish between xylem and phloem.

Solution 12

Xylem

Phloem

1. It conducts water and minerals.

2. Conducting channels or tracheary elements are tracheids and vessels.

1. It conducts organic solutes and food materials.

2. Conducting channels are sieve tubes.

Question 13

Distinguish between tracheids and vessels.

Solution 13

Tracheids

Vessels

1. Single celled.

2. The end walls remain intact.

1. Made up of a row of cells.

2. End walls get dissolved and become perforated.