NCTB Class 7 Science Chapter 2″ Cellular Organisation of Plants and Animals” Solution
Bangladesh Board Class 7 Science Solution Chapter 2 “Cellular Organisation of Plants and Animals” Solution Exercises Question and Answer by Experienced Teacher.
NCTB Solution Class 7 Chapter 2″Cellular Organisation of Plants and Animals”:
|Board||NCTB Bangladesh Board|
|Chapter Name||Cellular Organisation of Plants and Animals|
Fill in the blanks:-
(1) ——tissues are unable to divide.
(2) Plant tissues are of two type—–tissue and—tissue.
Ans:- Meristematic, Permanent.
(3) Cardiac muscle is a type of—.
Ans:- Involuntary muscle.
(4) Brain is composed of innumerable—-.
(5) ——–is the power house of cell.
Short answers questions:-
(1) Describe the functions of muscles.
Ans:- The functions of muscles:
(a) Muscles give shape of the body and help in bone movement.
(b) Help in movement and locomotion.
(c) It protects internal organs.
(d) Heart muscles help in blood circulation in the body.
(2) Write down the characteristics of epithelial tissues.
Ans:- Characteristics of epithelial tissues;
(a) Epithelial tissues are arranged in one or more strata.
(b) Cell are arranged on a thin foundation membrane.
(c) This type of tissues do not have any inter cellular matrix.
(3) Describe the structure of nucleus.
Ans:-The structure of nucleus:
Densest part of protoplasm covered by membrane is nucleus. It has four parts, (i) nuclear membrane, (ii) nucleolus, (iii) nuclear reticulum and (iv)nucleolus.
(4) Mention the functions of plastids.
Ans:- The functions of plastics:
(a) Synthesis of food.
(c) Storage of food.
(5) Describe the structure of a mitochondrion.
Ans:- The structure of a mitochondrion:
A mitochondrion is surrounded by two layers of membranes. Qatar layer is smooth but the inner one is folded inward like fingers these are called cristae.
Multiple choice questions:-
(1) Which of the following structure is absent in meristematic cell?
Ans:- (c) Cell vacuole.
(2) The cell vacuole contains-
Ans:- (a) (i) and (ii)
The function of figure A is-
Ans:- (b) (i) and (iii)
(4) Characteristics of A and B are-
Ans:- (a) (i)
(1) (a) What is blood?
Ans:- Blood is a liquid connective tissue which carriers substances (oxygen, food, Excretory substances) From one part to another in body and gives resistance against germs.
(1) (b) What is meant by epithelial tissue?
Ans:- Tissue that makes the open areas of the body cover and makes up the internal covering is called epithelial tissue.
(1) (c) Explain the importance of bones is figure P.
Ans:- The importance of bones in figure P is bones give mechanical support and help to bear the weight.
(1) (d) Compare the tissue of the figure P and Q.
(2) (a) What is a cell wall?
Ans:- In plant cell there is a hard and thick non-living wall, which is called well wall.
(2) (b) Why is the mitochondria called powerhouse?
Ans:- Mitochondrion is called ‘Power house’ because mitochondrion is the source of all energy used in metabolic activities in an organism.
(2) (c) Why is figure N coloured thought it is a root?
Ans:- Figure N is a root but it has colour because it has colour pigment in chloroplast which produces its colour.
(2) (d) Explain the changes of the plant in figure M that would occur after 8-10 days.
Ans:- If the plant is covered with tab for 8-10 days like figure M then plant becomes white, the chloroplast of the plant become white.