Saturday, April 20, 2013

Tissues class 9th


(Q.)Which tissue makes up the husk of coconut?
 (Ans)  Sclerenchyma (fibres)

(Q.)What is middle lamella?
 (Ans)  Wall between adjacent plant cells is known as middle lamella.

(Q.)Write two functions of stomata? 
 (Ans)  (i) Gaseous exchange (ii) Transpiration

(Q.)Name the tissue in which the matrix is not produced by the cells present in it.
(Ans)  Blood

(Q.)What is the unique property of sieve tubes?
(Ans)  Perforated walls.



(Q.)Write a brief note on muscle tissue?
 (Ans)  Muscle tissue consists of elongated cells called muscle fibres which have the ability to contract and relax. These are made up of special contractile proteins. Muscle tissues are responsible for the movement in our body.

(Q.)What is the function of collenchyma in plants?
(Ans)  Collenchyma allows flexibility in plants and easy bending in various parts of the plants without breaking. It also provides mechanical support to plants.


(Q.)What is the function of epidermis in plants?
(Ans)  It protects all the parts of the plant. Epidermal cells on the aerial parts of the plant secrete a waxy, water-resistant layer on their outer surface which aids in protection against loss of water, mechanical injury and invasion by parasitic fungi.


(Q.)What are the properties of xylem tracheids and vessels?
(Ans)  Xylem tracheids and vessels are dead cells and have lignified walls. In addition to conduction, these tissues serve to conduct water and also provide support.


(Q.)What is the function of xylem parenchyma and xylem fibres?
(Ans)  Xylem parenchyma stores food and helps in the sideways conduction of water while xylem fibres are mainly supportive in function.




(Q.)Where is cuboidal epithelium located?
(Ans)  Cuboidal epithelium is located in the glands and in the lining of the kidney tubules as well as in the ducts of the glands.




(Q.)What are the different types of epithelial tissue?
(Ans)  Squamous epithelium, cuboidal epithelium, columnar epithelium, ciliated epithelium,stratified, pseudostratified and glandular epithelium.

(Q.)What is the function of columnar epithelium in respiratory tract?
(Ans)  In the respiratory tract, the columnar epithelial tissue has cilia, which are hair-like projections on the outer surfaces of epithelial cells. These cilia move and their movement pushes the mucus forward to clear it.

(Q.)Write the function of areolar tissue.
(Ans)  It fills the space inside the organs, supports internal organs and helps in repair of tissues.

(Q.)What is the property of cartilage?
(Ans)  Cartilage has widely spaced cells called chondrocytes. Its solid matrix is composed of chondoitin . It provides support and flexibility to various structures like joints.

(Q.)Write the properties of voluntary muscles.
(Ans)  These muscles are made up of muscle fibres which are multinucleated, cylindrical and unbranched cells with light and dark bands (striations). These are under voluntary control and are associated with the skeletal system.

(Q.)Why cardiac muscles are unique?
(Ans)  These are uninucleated, cylindrical, branched cells with light and dark bands. These are present in heart and show rhythmic contraction and relaxation throughout life.

(Q.)What are neurons?
(Ans)
Neurons are the basic unit of the nervous system and consists of a cell body, a long axon and many short branches called dendrites. These help in transmission of signals within the body.

Tissues - 9th class

Tissue    -      Class-9th

(1 Mark)


(Q.)Which tissue makes up the husk of coconut?

 (Ans)  Sclerenchyma (fibres)


(Q.)What is middle lamella?

 (Ans)  Wall between adjacent plant cells is known as middle lamella.


(Q.)Write two functions of stomata? 

 (Ans)  (i) Gaseous exchange (ii) Transpiration


(Q.)Name the tissue in which the matrix is not produced by the cells present in it.

(Ans)  Blood


(Q.)What is the unique property of sieve tubes?

(Ans)  Perforated walls.


(2 Marks)


(Q.)Write a brief note on muscle tissue?

 (Ans)  Muscle tissue consists of elongated cells called muscle fibres which have the ability to contract and relax. These are made up of special contractile proteins. Muscle tissues are responsible for the movement in our body.


(Q.)What is the function of collenchyma in plants?

(Ans)  Collenchyma allows flexibility in plants and easy bending in various parts of the plants without breaking. It also provides mechanical support to plants.

(Q.)What is the function of epidermis in plants?

(Ans)  It protects all the parts of the plant. Epidermal cells on the aerial parts of the plant secrete a waxy, water-resistant layer on their outer surface which aids in protection against loss of water, mechanical injury and invasion by parasitic fungi.

(Q.)What are the properties of xylem tracheids and vessels?

(Ans)  Xylem tracheids and vessels are dead cells and have lignified walls. In addition to conduction, these tissues serve to conduct water and also provide support.

(Q.)What is the function of xylem parenchyma and xylem fibres?

(Ans)  Xylem parenchyma stores food and helps in the sideways conduction of water while xylem fibres are mainly supportive in function.

(Q.)Where is cuboidal epithelium located?

(Ans)  Cuboidal epithelium is located in the glands and in the lining of the kidney tubules as well as in the ducts of the glands.

(Q.)What are the different types of epithelial tissue?

(Ans)  Squamous epithelium, cuboidal epithelium, columnar epithelium, ciliated epithelium,stratified, pseudostratified and glandular epithelium.

(Q.)What is the function of columnar epithelium in respiratory tract?

(Ans)  In the respiratory tract, the columnar epithelial tissue has cilia, which are hair-like projections on the outer surfaces of epithelial cells. These cilia move and their movement pushes the mucus forward to clear it.

(Q.)Write the function of areolar tissue.

(Ans)  It fills the space inside the organs, supports internal organs and helps in repair of tissues.


(Q.)What is the property of cartilage?

(Ans)  Cartilage has widely spaced cells called chondrocytes. Its solid matrix is composed of chondoitin . It provides support and flexibility to various structures like joints.

(Q.)Write the properties of voluntary muscles.

(Ans)  These muscles are made up of muscle fibres which are multinucleated, cylindrical and unbranched cells with light and dark bands (striations). These are under voluntary control and are associated with the skeletal system.

(Q.)Why cardiac muscles are unique?

(Ans)  These are uninucleated, cylindrical, branched cells with light and dark bands. These are present in heart and show rhythmic contraction and relaxation throughout life.

(Q.)What are neurons?

(Ans)Neurons are the basic unit of the nervous system and consists of a cell body, a long axon and many short branches called dendrites. These help in transmission of signals within the body.

 

(5 Marks)

 Q.)What are the functions of connective tissue?

(Ans)  The functions of connective tissue are as follows:
1. It has jelly-like ground substance, which acts as lubricant.
2. Bones and cartilage form skeleton and protect the delicate organs of
body.
3. Adipose tissue, another kind of connective tissue, helps in storage of
fats.
4. Plasma cells make antibodies.
5. Fluid connective tissues (blood and lymph) help in transport of materials.


(Q.)Differentiate between:

(a) Simple tissue and complex tissue

(b) Parenchyma, collenchyma and sclerenchyma

(Ans)  (a)
Simple tissue
Complex tissue
Simple tissue is a group of single type of cells, e.g., parenchyma, sclerenchyma andcollenchyma.
Complex tissue is made up of more than one type of cells and they work together as a unit, e.g. xylem & phloem.
(b)
Parenchyma
Collenchyma
Sclerenchyma
The cell wall is without any thickening.
Cell wall is irregular and thickened at corners.
The walls are thick due to presence of lignin. Often the thickening is so much that there is no internal space inside the cell.

(Q.)(i) Name the plant tissue found in the husk of a coconut.

(ii) Identify the chemical that is responsible for its stiffness.

(iii) Give three ways in which it differs from parenchymatous cells.

(5 Marks)

(Ans)  (i) Sclerenchyma
(ii) Lignin
(iii) The three points of differences are:
 

Sclerenchyma                                         Parenchyma       

It consists of dead cells.                           It consists of living cells.      
Have very thick walls.                              Have very thin walls.      
Provides strength to plant parts.             Stores food.     

(Q.)Give one term for the following:

(i) Structure that takes impulses away from a neuron.

(ii) Meristematic tissue that increases the girth in plants.

(iii) Space found between the cells of the connective tissue.

(iv) Small pores found on the epidermis of a plant leaf.

(v) Protective covering of various organs in animals.

(5 Marks)

(Ans)  (i) Axon
(ii) Lateral meristem
(iii) Matrix
(iv) Stomata
(v) Epithelial Tissue

(Q.)Answer each of the following in one word or one sentence:

(i) What makes the bone matrix hard?

(ii) Which tissue is responsible for moving our hands up and down?

(iii) Name the part of phloem that is nucleated.

(iv) Give another term for striated muscles.

(v) Name the only living cell of xylem.

(5 Marks)

(Ans)  (i) Calcium and phosphorus makes the bone matrix hard.
(ii) Muscular tissue helps in the up and down movement of the hands.
(iii) The part of the phloem that is nucleated is Companion cells.
(iv) Striated muscles are also called as Skeletal or Voluntary muscles.
(v) Xylem parenchyma are the only living cells found in xylem.

(Q.)Identify the type of tissue in the following and state one function of each:

(i) Skin

(ii) Heart muscles

(iii) Lining of Kidney tubule

(3 Marks)

(Ans)  (i) Skin – stratified squamous epithelium prevents wear and tear.

(ii) Heart muscles – cardiac muscles help in rhythmic contraction and relaxation of the heart.

(iii) Lining of kidney tubule – cuboidal epithelium provides mechanical support.

(Q.)(i) “Epidermal cells are protective in nature”. Justify and support your answer with two examples.

(ii) Name the structure that receives impulse in neuron.

(3 Marks)

(Ans)  (i) Epidermis plays a protective role. It protects all the external parts of a plant against loss of water.
a) In some desert plants, the epidermis has a thick waxy coating of cutin that prevents water loss from the plants.
b) Epidermal cells on the aerial parts of the plant secrete a waxy, water resistant layer, on the outer surface that helps in protection against loss of water and mechanical injury.
(ii) Dendrite receives impulses in neuron.

(Q.)What are the differences between striated, unstriated and cardiac muscles?
(5 Marks)
(Ans)  The differences between striated, unstriated and cardiac muscles are as follows:
Striated muscles
Unstriated (Smooth) muscles
Cardiac muscles
1. They are found in limbs, tongue, pharynx etc.
1. They are present in the wall of visceral organs.
1. They form the heart.
2. Long, cylindrical with blunt ends.
2. Short, spindle shaped with pointed ends.
2. Short, branched and cylindrical with flat ends.
3. Multinucleate, nuclei peripheral.
3. Uninucleate, nucleus in the center.
3. one or two nuclei in the center.
4. They are voluntary in action.
4. They are involuntary in action.
4. They are involuntary in action.
5. Dark and light bands are present.
5. No bands present.
5. Bands present.

Find Least Common Multiple (LCM). 1) 5 and 15 = ...