NCERT solutions for class 7 science chapter 11

NCERT solution class 7 chapter -Transportation in Animals and Plants

Transportation in Animals and Plants

 

Q1. Match structures given in Column I with function given in Column II.

          Column I            Column  II
(i)   Stomata

(ii)   Xylem

(iii)  Root  hairs

(iv)   Phloem

(a)     Transpiration

(b)     Transport of water

(c)      Absorption of water

(d)      Transport of food.

Ans.

(i) The blood from the heart is transported to all parts of the body by the body by the —- arteries —- .

(ii) Haemoglobin is present in —- red blood —- cells.

(iii) Arteries and veins are joined by a network of —- capillaries—- .

(iv) The rhythmic expansion and contraction of the heart id called  —- heartbeat —- .

(v) The main excretory product in human beings is —- urea—

(vi) Sweet contains water and. —- salts —-

(vii) Kidneys eliminate the waste materials in the liquid form called —- urine —- .

(viii) Water reaches great heights in the trees because of suction pull caused by —- transpiration—- .

Q.3.Choose the correct options:

(a) In plants, water is transported through
(i) Xylem (ii) Phloem (iii) Stomata (iv) Root hair
(b) Water absorption through roots can be increased by keeping the plants
(i) In the shade (ii) in dim light (iii) under the fan (iv) covered with a polythene bag

Ans.(a) (i) Xylem (b) (iii) under the fan

Q4. Why is transport of materials necessary in a plant or an animal? Explain.

Ans.Transport of materials is necessary for plants or animals because due to it the nutrients and oxygen are made available to all the parts of the body. If the transport of necessary nutrients and oxygen does not take place in the body, the body will not be able to survive.

Q5.What will happen if there are no platelets in the blood?

Ans. The blood platelets are responsible or the clotting of the blood. When some injury occurs blood starts flowing. But it clots on its own. If there are no platelets, the blood will not be able to clot and keep on flowing. Huge loss of blood ultimately causes death.

Q6.What are stomata? Give two junction stomata.

Ans.  Tiny pores present on the leaf surface are known as stomata.

Functions of stomata

  • Helps in exchange of gases
  • Evaporation of water through leaves occurs due to stomata.

Q7. Does transpiration serve any useful function in plants? Explain.

Ans. Transpiration serves the following functions in plants

  • It helps in lowering temperature of plants, thus preventing heat injury of plants.
  • Helps in transpiration pull, which helps in raining water in higher plants.
  • It also causes loss of water absorbed by plants.

Q8. What are the components of blood?
Ans.There are four components of blood:
(i) Plasma is a liquid part of blood which is yellowish in colour and contain 90% water. It contains food, enzymes, wastes and proteins etc
(ii) Red blood cells are disc shaped cells containing red coloured pigment called haemoglobin in it. Haemoglobin helps in transportation of oxygen.
(iii) White blood cells are the fighting cells which protect us against bacteria and foreign materials causing infections.
(iv) Platelets help in clotting of the blood

Q9. Why is blood needed by all the parts of a body?

Ans. Blood is needed by all the parts because it contains the digested food and oxygen in it. It supplies the oxygen and digested food to various parts of the body to provide essential energy to them which helps the body to perform various functions

Q10.What  makes blood look red?

Ans.  A red pigment called haemoglobin gives the blood its red colour. This pigment helps in carrying oxygen to various parts of the body by blood

Q11. Describe the function of the heart.

Ans. The right auricle and ventricle receive blood with carbon dioxide from all parts of the body. The collected blood is then pumped to the lungs for the purification. In lungs, the exchange of gases takes place and purified blood is sent back to left auricle. It pumps it to the left ventricle, which in turn pumps off the purified blood to all parts of body through arteries

Q12. Why is necessary to excrete waste products?

Ans. Certain waste and toxic products are formed during functioning of body cells. The waste products like urea etc. are toxic. When these toxic materials are not removed from the body, they get mixed with blood and can damage the cells of body. It is necessary to remove such poisonous waste materials from our body.

 

 

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