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 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.
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 .
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