Q.1.Match structures are given in Column I with functions given in Column II.
Q.2.-Fill in the blanks :
(i) The blood from the heart is transported to all parts of the body by the _____________
(ii) Haemoglobin is present in ___________ cells.
(iii) Arteries and veins are joined by a network of ___________ .
(iv) The rhythmic expansion and contraction of the heart is called ___________
(v) The main excretory product in human beings is ___________
(vi) Sweat contains water and .
(vii) Kidneys eliminate the waste materials in the liquid form called.
(viii) Water reaches great heights in the trees because of suction pull caused by.
(i) arteries
(ii) red blood cells
(in) capillaries
(iv) heartbeat
(v) urea
(vi) salts
(vii) urine
(viii) 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
(a) (i) Xylem
(b) (iii) under the fan
Q.4.Why is the transport of materials necessary in a plant or an animal? Explain.
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.
Q.5.What will happen if there are no platelets in the blood?
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Q.6.What are stomata? Give two junctions of stomata.
There are small openings on the lower surface of the leaves. These pores are called stomata. These openings are surrounded by guard cells.
Functions of stomata:
1. It helps in the transpiration of water, i.e., the loss of excess water from the plant.
2. Loss of water from the stomata creates an upward pull, i.e., suction pull which helps in the absorption of water from the roots.
3. They help in the exchange of gases.
Q.7.Does transpiration serve any useful function in plants? Explain.
(i) It helps to enhance the absorption of water and dissolved minerals by the creation of a suction pull.
(ii) It helps in getting rid of the excess water.
(iii) It helps in the transport of water and minerals to leaves and leaves that use the water for photosynthesis. ‘
(iv)It produces a cooling effect on the plant
Q.8.What are the components of blood?
There are four components of blood:
(i) Plasma is a liquid part of blood that 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. Haemoglobin helps in the transportation of oxygen.
(iii) White blood cells are the fighting cells that protect us against bacteria and foreign materials causing infections.
(iv) Platelets help in the clotting of the blood
Q.9.Why is blood needed by all the parts of a body?
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
Q.10.What makes the blood look red?
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
Q.11.Describe the function of the heart.
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 purification. In the lungs, the exchange of gases takes place and purified blood is sent back to the left auricle. It pumps it to the left ventricle, which in turn pumps off the purified blood to all parts of the body through arteries
Q.12.Why is it necessary to excrete waste products?
Certain waste and toxic products are formed during the functioning of body cells. 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 the body. It is necessary to remove such poisonous waste materials from our bodies.
Q.13.Draw a diagram of the human excretory system and label the various parts.
