Living Science Biology Class 7 ICSE Solutions Chapter 3 Tissues, Organs and Organ Systems in Plants and Animals

ICSE Living Science Biology for Class 7 Solutions Chapter 3 Tissues, Organs and organ systems in plants and animals

Check Your Progress

State if the following statements are true or false. Correct the statement if it is false.

Question 1.
Meristematic tissues responsible for lateral growth are called cambium.
Answer:
True

Question 2.
A permanent tissue is a group of young cells that have the capability of active cell division.
Answer:
False. A meristematic tissue is a group of young cells that have the capability of active cell division.

Question 3.
Collenchyma tissue gives mechanical strength to the stem where it is present.
Answer:
False. Sclerenchyma tissue gives mechanical strength to the stem where it is present.

Question 4.
Phloem parenchyma is the only living component of xylem.
Answer:
False. Xylem parenchyma is the only living component of xylem.

Question 5.
Specialized .parenchyma cells, closely associated with sieves cells are known as companion cells.
Answer:
True

Check Your Progress

Question 1.
epithelium occurs in the thyroid gland.
Answer:
Cuboidal epithelium occurs in the thyroid gland.

Question 2.
epithelium lines the blood vessels and oesophagus, and forms the epidermis of the skin.
Answer:
Squamous epithelium lines the blood vessels and oesophagus, and forms the epidermis of the skin.

Question 3.
Voluntary muscles are also called muscles.
Answer:
Voluntary muscles are also called skeletal muscles.

Question 4.
muscle cells have only one nucleus and have no striations.
Answer:
Involuntary muscle cells have only one nucleus and have no striations.

Question 5.
tissue provides protective padding around organs.
Answer:
Adipose tissue provides protective padding around organs.

Check Your Progress

Answer these questions.

Question 1.
Name the major organs of the human digestive system.
Answer:
The major organs of the human digestive system are stomach, liver, pancreas, intestines (small and large), mouth and
oesophagus.

Question 2.
What is the function of the circulatory system ?
Answer:
Circulatory system transports materials throughput the body It includes heart, arteries, veins and capillaries,

Question 3.
Name the organ system that receives and traftspdrts messages throughout the body.
Answer:
Nervous system.

Question 4.
Name any one plant organ.
Answer:
Leaf ,

Knowledge-Based Questions

A. Tick the most appropriate answer.

Question 1.
Meristematic tissues have
a. continuously dividing cells.
b. dead cells
c. cells which divide for a short period
d. cells which do not divide at all
Answer:

Question 2.
Which of the following tissues do not possess living protoplasm at maturity ?
a. Collenchyma
b. Phloem
c. Parenchyma
d. Xylem
Answer:
d. Xylem

Question 3.
Phloem consists of –
a. vessels, collenchym? and phloem fibres.
b. tracheids, phloem fibres and phloem parenchyma.
c. sieve cells phloem fibres and phloem parenchyma.
d. vessels, sieve tubes, xylem fibres and phloem parenchyma.
Answer:
c. sieve cells phloem fibres and phloem parenchyma.

Question 4.
Vascular bundles consists of
a. parenchyma and sclerenchyma
b. collenchyma and xylem
c. phloem and vessels
d. phloem and xylem
Answer:
d. phloem and xylem

Question 5.
Voluntary muscles are
a. cylindrical and branched
b. cylindrical and unbranched
c. spindle shaped
d. spherical
Answer:
b. cylindrical and unbranched

Question 6.
The short thread-like branches arising from the cell body of a nerve cell are called
a. cytons
b. axons
c. neurons
d. dendrites
Answer:
d. dendrites

Question 7.
The white fibrous tissue present in tendons joins
a. bone to a bone
b. bone to a muscle
c. muscle to a muscle
d. all of these
Answer:
b. bone to a muscle

Question 8.
Blood has a straw-coloured fluid matrix called
a. plasma
b. stroma
c. bone
d. vacuole
Answer:
a. plasma

B. Fill in the blanks.

Question 1.
………………… tissue is situated at the tip of the root and stem.
Answer:
Apical meristematic tissue is situated at the tip of the root and stem.

Question 2
………………. tissue in plants consists of more than one kind of cells.
Answer:
Complex permanent tissue in plants consists of more than one kind of cells.

Question 3
…………… is a complex tissue that distributes food in plants.
Answer:
Phloem is a complex tissue that distributes food in plants.

Question 4.
Epithelial tissue consists of cells without any ………………. spaces.
Answer:
Epithelial tissue consists of cells without any intercellular spaces.

Question 5.
………………. muscles help in the movement of the limbs.
Answer:
Voluntary muscles help in the movement of the limbs.

Question 6.
The …………. or nerve fibres constitute the nerves.
Answer:
The neurons or nerve fibres constitute the nerves.

Question 7.
A ……………….. connects one bone to another.
Answer:
A ligament connects one bone to another.

Question 8
………………… tissue cushions and insulates the body.
Answer:
Adipose tissue cushions and insulates the body.

Question 9.
The matrix of bone is filled w ith cells called ……………….
Answer:
The matrix of bone is filled with cells called osteocytes.

Question 10
………….. is a fluid connective tissue without red blood cells.
Answer:
Lymph is a fluid connective tissue without red blood cells.

C. Define the following terms.

1. collenchyma
2. connective tissue
3. adipose tissue
4. connective tissue proper
5. cartilage
6. voluntary muscles
Answer:
1. Collenchyma is a simple permanent tissue of plant made of living cells, found below the epidermis in young stems and petioles of leaves. It provides structural support to growing stems and leaves.

2. Connective tissue is the tissue in animals which joins different parts of the body and provides support to them. It also fills up the space between various organs. It consists of cells with spaces between them.

3. Adipose tissue is a type of connective tissue proper in animals which stores energy in the form of fat and insulates, cushions and provides protective padding around organs.

4. Connective tissue proper is a type of connective tissue in animals which connects bones to muscles (tendons), bones to other bones (ligaments) and gives support by filling up spaces between the organs, (areolar tissue, adipose tissue, yellow fibrous tissue and white fibrous tissue).

5. Cartilage is a type of solid connective tissue (skeletal tissue) which is highly elastic and resistant to crushing and hence relieves the bones of shocks.

6. Voluntary muscles are types of muscular tissue which are under our control and help in the movement of the bones. These are also called skeletal muscles or striated muscles.

D. State if the following statements are true or false. Correct the statement if it is false.

Question 1.
Sclerenchyma cells are dead cells with no protoplasmic content.
Answer:
Time

Question 2.
Voluntary muscles are present in the internal organs of the body.
Answer:
False. Involuntary muscles are present in the internal organs of the body.

Question 3.
Cardiac muscles have dark and light bands.
Answer:
Time

Question 4.
The yellow fibrous tissue, a type of connective tissue, is found in ligaments.
Answer:
True

Question 5.
Fluid-filled spaces in which cartilage cells are present are called lacunae.
Answer:
True

Question 6.
RBCs and WBCs are formed in the bone marrow.
Answer:
True

E. Differentiate between

Question 1.
apical meristematic tissue and lateral meristematic tissue!
Answer:
Apical meristematic tissue :

• This is a group of cells (tissue) present on the root tip and shoot tip.
• It helps in increasing height of the plant.

lateral meristematic tissue :

• This tissue is present between xylem and phloem
• It helps in increasing diameter of plant.

Question 2.
meristematic and permanent tissue.
Answer:
Meristematic tissue :

• The cells of meristematic tissue have the capacity of active cell division.
• This tissue is found in root tip and shoot tip.
• It helps in growth of plant.
• It does not help in cond-uction of nutrients and water.

Permanent tissue :

• In permanent tissue growth of cells has either stopped completely or for the time being.
• This tissue is present in leaves, stems, flowers, roots, fruits, seeds.
• It provides support and protection.
• This tissue also helps in conduction of nutrients and water.

Question 3.
parenchyma and sclerenchyma.
Answer:
Parenchyma :

• The cells are thin walled
• The cells are living.
• Protoplasm is present.
• Cells of this tissue store food material.

Sclerenchyma :

• The cell wall of the cells is thickened all over.
• The cells are non living.
• Protoplasm is absent.
• This tissue provides mechanical strength to the stem of the plant.

Question 4.
simple permanent tissue and complex permanent tissue.
Answer:
Simple permanent tissue :

• The cells of this tissue are structurally and functionally similar.
• Parenchyma, collenchyma and sclerenchyma are the simple permanent tissue.
• This tissue, helps in storage of food, provides mechanical strength.

Complex permanent tissue :

• This tissue is made up of more than one kind of cells.
• Xylem and phloem are the complex permanent tissue.
• This tissue helps in conduction of food and water.

Question 5.
voluntary muscle and involuntary muscle.
Answer:
Voluntary muscle :

• These muscles are under our control or will.
• These muscles have many nuclei.
• These muscles are present in our limbs.
• These muscle, are also called striated muscles as they have dark and light bands.
• They are cylindrical but do not branch.

involuntary muscle :

• These muscles are not under our control or will.
• These muscles have one nucleus.
• These muscles are present in the internal organs of body.
• These muscles are also called unstriated muscles as they do not have striations.
• They are spindle shaped.

Question 6.
bone and cartilage.
Answer:
Bone :

• The bone forming cells are called osteocytes.
•  It is the hardest connective tissue.
•  It is not elastic tissue.
• Location : It forms the endoskeleton of adult vertebrates.

Cartilage :

• Tire cartilage forming cells are called chondrocytes.
• It is softer than bone.
• It is elastic tissue.
• Location : found covering the ends of long bones, trachea branchi, external pinna

F. Find the odd one out. Give reasons for your answer.

Question 1.
parenchyma, collenchyma, vascular bundles, sclerenchyma.
Answer:
Vascular bundles, because vascular bundles are the complex permanent tissue and the rest are the types of simple pennanent tissue.

Question 2.
Sieve cells, phloem fibres, xylem parenchyma, phloem parenchyma.
Answer:
Xylem parenchyma, because it is the part of xylem and the rest constitute the phloem.

Question 3.
tendon, squamous epithelium, ligament, bone.
Answer:
Squanous epithelium, because it is epithelial tissue and tie rests are the types of connective tissue.

Question 4.
lymph, white fibrous tissue, yellow fibrous tissue, areolar tissue. –
Answer:
lymph, because it is fluid connective tissue and the rests are the types of connective tissue proper.

Question 5.
thrombocytes, erythrocytes, lacunae, leucocytes
Answer:
lacunae, because lacunae are the fluid filled spaces in cartilage and the rests are the cells present in the blood. ,

G Answer the following in short.

Question 1.
Which tissue is responsible for the increase in the height of a plant ? Where is it located ?
Answer:
Apical meristematic tissue is responsible for the increase in die height of a plant. This tissue is present at the root tip : and shoot tip. The cells of this tissue are usually small, thin walled and full of cytoplasm. They have a large nucleus. These cells divide rapidly and continuously, die plant thereby ‘ gains height. Meristematic tissue is present in the growing , parts of a plant, such as root tip and shoot tip.

Question 2.
What constitutes the vascular system of the plant ? .
Answer:
Xylem and phloem, which are the complex permanent tissues together constitute the vascular system of the plant. These tissues extend from the tip of the root to the tip of die leaf.

Question 3.
What is a neuron ?
Answer:
The cells’ tiiat constitute the nervous tissue are called neuron , or nerve cells. The neuron is the smallest part of nervous tissue.

Question 4.
Where is the white fibrous tissue found in human body?
Answer:
The white fibrous tissue is found in tendons. Tendons connect the muscles to the bones. This tissue has : considerable strength and high elasticity.

Question 5.
What are cardiac muscles ? What is special about them?
Answer:
Cardiac muscles are types of involuntary muscles which are ~ present only in the heart. They are uninucleate, striated and cause the rhythmic movement if the heart resulting in circulation of blood in the body.,Cardiac muscles are special because they work continuously and tirelessly throughout the life.

H. Answer the following in detail.

Question 1.
State the differences between parenchyma, collenchyma and sclerenchyma tissues.
Answer:

Question 2.
What are the various types of cells present in xvlem ? Write their functions.
Answer:
Xylem is water conducting tissues of the plant. The cells of the Xylem are thick walled. It consists of four types of cells. These are :
(i) Vessels
(ii) tracheids
(iii) fibres
(iv) Xylem parenchyma.

• A Xylem Vessel is not a single cell but it is a series of cells that are joined from end to end thereby forming a long tube.
• Tracheids are long and nanow cells which taper at ends. Both Xylem vessels and tracheids do not have living protoplasm at maturity and are involved in the upward transportation of water.
• Fibres provide strength to this tissue. They also do not have living protoplasm at maturity.
• Xylem parenchyma is the only living component of xylem. It helps in conduction of water and storage of food.

Question 3.
Name the various types of animal tissues and state their functions.
Answer:
The four types of animal tissues are :
(i) Epithelial tissues
(ii) Muscular tissues
(iii) Nervous tissues
(iv) Connective tissues

(i) Functions of epithelial tissues
(a) They form the protective internal lining of organs and cover the external body surface.
(b) In salivary and gastric (stomach) glands, the epithelial tissue is specialized to secrete enzymes and hormones.
(c) They absorb nutrients from the digested food from the lining of the small intestine.
(d) The excrete waste products from the body from sweat glands and kidneys.

(ii) Functions of muscular tissues –
(a) Voluntaiy muscles help in the movement of bones.
(b) Involuntary muscles help in the movement of food, movement of urine from urinary bladder, etc.
(c) Cardiac muscles cause the rhythmic movement of the heart resulting in circulation of blood in the body.

(iii) Functions of nervous tissue –
(a) This tissue helps in the control and co-ordination of the body by sending message or nerve impulse from body parts to the brain and spinal cord.

(iv) Functions of connective tissue –
(a) It joins different tody parts like bone to muscle, bone to bone, etc.
(b) It fills up the space between various organs and acts as a packing material.
(c) It provides insulation to the body apd cushions and supports it.
(d) Fluid connective tissues (blood) carry oxygen and carbon dioxide to and from various body parts, provide protection from foreign bodies and help in blood clotting.

Question 4.
Explain the structure and functions of various types of epithelial tissue.
Answer:
Epithelial tissue forms the continuous sheet of cells that v covers the external surface of the body as well as the linings of the internal organs. There is no intercellular space between the cells of epithelial tissue, as they are placed very close to each other. On the basis of the shape of cells : Epithelial tissue is classified in to three types :

(a) Squamous Epithelium : The cells are hexagonal or irregular in shape. The cells are very thin that the surface below which the nuclei are present becomes raised. This tissue is found in the lining of body cavity, blood vessels,
cheeks etc.

(b) Cuboidal Epithelium : The cells are cube like or isodiametric. The nucleus is centrally located. This tissue is found in the nephrons of kidneys, salivary glands, sweat glands etc.

(c) C’ulumnar Epithelium : The cells of this tissue are pillar or column like. The cells are placed side by side like columns. The nucleus is towards the base of the cells. This tissue is found in the lining of the alimentary canal, the sensory organs etc.

(d) Functions of epithelial tissues CO They form the protective internal lining of organs and cover the external body surface.
(ii) In salivary and gastric (stomach) glands, the epithelial tissue is specialized to secrete enzymes and hormones.
(iii) They absorb nutrients from the digested food from the lining of the small intestine.
(iv) The excrete waste products from the body from sweat glands and kidneys.

Question 5.
Describe connective tissue. How is it different from other tissues ?
Answer:
Connective tissue joins different parts of the body and provides support to them. It also fills up the space between various organs. Depending upon their structure and function, connective tissue is of three types :

(i) Connective tissue proper – It is of following types –
(a) Areolar tissue – It forms a continuous layer under the skin, fills up spaces between organs and acts up spaces between organs and acts as a packing material around the organs.
(b) Yellow fibrous tissue – It is found in ligaments (which join the bones) and arteries walls.
(c) White fibrous tissue – It is found in tendons (which connect muscles to the bones)
(d) Adipose tissue – Present around internal organs and beneath the skin, it stores energy as fat, cushions and insulates the body and provides protective covering around the organs.

(ii) Skeletal tissue – It is the solid connective tissue which provides support to the body and forms endoskeleton (internal skeleton) of vertebrates.

It is of two types –
(a) Cartilage – It relieves the bones of shocks and reduces friction between them.
(b) Bone – The are strong and hard. Red blood cells and white blood cells are formed in the bone marrow.

(iii) Fluid, connective tissue – It is of two types –
(a) Blood – It has a straw – coloured fluid matrix called plasma in which three types of cells are present-erythrocytes (Red blood cell, RBC), leucocytes (white blood cell, WBC) and thrombocytes (platelets). RBCs cany oxygen and carbon
dioxide to and from various body parts to the lungs. WBCs provide protection from foreign bodies. Platelets help in blood clotting.

(b) Lymph – It lacks RBCs and play important role in protecting body against infection. Connective tissue is different from other tissues because it has cells which are separated from each other. The space between the cells is composed of different intercellular substances that fomi the matrix or ground substance. The living cells produce the non-living matrix, which could be a liquid (in blood), semi-solid (connective tissue proper) or solid (bone).

I. Given below is a table showing structures found in plants or in the human body.

Identify these structures, give their location and write one important function of each.
Answer:
structure

Name – Voluntary muscles
Location – Hands, legs, tongue, jaws, trunk, etc.
Function – Help the movement of bones

Name – Xylem
Location – In vascular bundle from root tip to leaf tip
Function – 1 ransportation of water and storage of food.

Name : Pareelnma
Location : Almost all plant parts
Function : Help i:t photosynthesis and store food material

Name : Apical meristematic tissue
Location : Root tip and shoot tip
Function : Helps, plant to grow and gain height

(d) Adipose tissue – Present around internal organs and beneath the skin, it stores energy as fat, cushions and insulates the body and provides protective covering around the organs.

(ii) Skeletal tissue – It is the solid connective tissue which provides support to the body and forms endoskeleton (internal skeleton) of vertebrates. It is of two types –
(a) Cartilage – It relieves the bones of shocks and reduces friction between them.
(b) Bone – The are strong and hard. Red blood cells and white blood cells are formed in the bone marrow.

(iii) Fluid connective tissue – It is of two types –
(a) Blood – It has a straw-coloured fluid matrix called plasma in which three types of cells are present-erythrocytes (Red blood cell, RBC), leucocytes (white blood cell, WBC) and thrombocytes (platelets). RBCs cariy oxygen and carbon dioxide to and from various body parts to the lungs. WBCs provide protection from foreign bodies. Platelets help in blood clotting.

(b) Lymph – It lacks RBCs and play important role in protecting body against infection. Connective tissue is different from other tissues because it has cells which are separated from each other. The space between the cells is composed of different intercellular substances that form the matrix or ground substance. The living cells produce the non-living matrix, which could be a liquid (in blood), semi-solid (connective tissue proper) or solid (bone).

J. Given below is a table showing structures found in plants or in the human body.

Identify these structures, give their location and write one important function of each.
Answer:

Name : Cuboidal epithelium
Location : Thyroid gland, kidney tubules, salivary glands, pancreas, liver.
Function : Protect internal organs, excrete waste from body, secrete enzyme and hormones

Name : Adipose tissue
Location : Beneath the skin and around internal organs Function : Store energy in form of fat, insulates body, provides protective padding around organs.

K. Identify the following diagrams and label the parts marked.
L. Some of the parts of the nerve cell are marked incorrectly.

Write the correct names in the space provided.

Living Science Biology Class 7 ICSE Solutions