Match the words of Column (A) with that of Column (B)

Column (A)	Column (B)
(a) Phloem	(i) Excretion
(b) Nephron	(ii) Translocation of food
(c) Veins	(iii) Clotting of blood
(d) Platelets	(iv) Deoxygenated blood

Ans. (a)-(ii), (b)-(i), (c)-(iv), (d)-(iii)

Artery	Vein
1. Have thick elastic, muscular walls.	1. Have thin, non-elastic, walls.
2. Lumen is narrow.	2. Lumen is wide.
3. Carry blood from heart to all body parts.	3. Carry blood from all body parts to heart.
4. Carry oxygenated blood (except pulmonary artery).	4. Carry deoxygenated blood (except pulmonary vein).

 

Leaves show following adaptations for photosynthesis:
 (a) Flat surface to allow greater exposure to sunlight
 (b) Presence of chlorophyll to trap solar energy
 (c) Larger number of stomata on lower surface. 

 

The food of herbivores contains a huge amount of cellulose. The animals need the assistance of certain bacteria to digest cellulose and this process takes time. Due to this, herbivores have longer small intestine than carnivores. Meat is easier to digest and hence carnivores have small intestine which is much smaller than in herbivores.

Mucus plays important role in digestive system. Mucus prevents the inner lining of digestive system from becoming dry. This helps in easier movement of food through the digestive system. Moreover, mucus in stomach protects the inner lining from damage by hydrochloric acid. So, lack of mucus will result in damage to the inner lining of stomach. It may result in gastric ulcers.

Fat is present in the form of large globules. For the concerned enzyme, it is difficult to digest large globules of fat. Emulsification of fat results in fat breaking into smaller globules. After that, becomes easier for the enzyme to digest fat.

Alimentary canal has muscular walls. Due to this, the alimentary canal contracts and relaxes in alternative fashion. This movement in alimentary canal is called peristalsis. Food moves inside the alimentary canal because of peristalsis.

Small intestine has specialized structures to facilitate absorption. The inner lining of small intestine has numerous folds; to increase the area of absorption. The finger-like projections inside the small intestine are richly supplied by blood vessels. This also helps in absorption of food. Due to this, absorption of digested food occurs mainly in the small intestine.