1. What is common for cuscuta, ticks and leeches.
Ans. Cuscuta, ticks and leeches, all have parasitic mode of nutrition, they harm their host while taking nutrition.
2. What advantage over an aquatic organism does a terrestrial organism have with regard to obtaining oxygen for respiration.
Ans. The advantages are:
(i) Increased respiratory surface area.
(ii) Very fine and delicate surface for easy exchange of oxygen and carbon – dioxide.
(iii) Placement of respiratory surface within the body for protection
(iv) Mechanism for moving the air in and out of the respiratory surface where the oxygen is absorbed.
3. Differentiate between single and double circulation found in vertebrates.
Ans.
4. Name the substrates for the following enzymes
a) Trypsin b) Amylase c) Pepsin d) Lipase
Ans. a) Protein b) Starch c) Protein d) Lipids
5. What are the two stages in photosynthesis.
Ans. Two stages in photosynthesis –
(a) Light reaction – Light energy breaks up water molecular into hydrogen and oxygen, called photolysis of water
(b) Dark reaction – Fixation and conversion of carbon dioxide into a simple carbohydrate like glucose.
6. What is the difference between arteries and veins?
Ans.
| ARTERIES | VEINS |
| 1. It carries blood away from the heart. | It carries blood towards the heart. |
| 2. They are thick walled. | They are thin walked |
| 3. They carry blood away from the heart | They carry blood away from the heart |
| 4. No valves are present | Valves are present |
| 5. It carries oxygenated blood. | It carries deoxygenated blood. |
7. What is villi. What are its functions.
Ans. Finger like projection present in the inner lining of small intestine are called villi. They increase the surface area for the absorption of digested food in the small intestine.
8. What type of respiration takes place in human muscles during vigorous exercise and why.
Ans. During vigorous exercise, anaerobic respiration takes place in human muscles. During exercise our energy requirement increase, so our striated muscles start respiring anaerobically in the lack of oxygen and producers ATP molecules.
9. How is opening and closing of stomata regulated.
Ans. The closing and openings of the stomata is regulated by guard cells. When the guard cells swell or turgid due to entry of water, the stomata are opened. The guard cells shrink due to loss of water the stomata get closed.
10. State two vital functions of kidney.
Ans. Functions of the kidney are –
1) It maintains water balance in the body tissues.
2) It controls calcium levels in the blood to maintain healthy bones.
11. Differentiate between aerobic and anaerobic respiration.
Ans.
12. Meat is easier to digest as compared to grass. Why.
Ans. It is easier to digest meat because our digestive juices contain enzymes which can easily digest meat but our body does not digest cellulose which is a main component of grass.
13. Differentiate between transport of materials in xylem & phloem
Ans.
14. What is the role of glomerulus in kidney.
Ans. Glomerulus is a group of capillaries present in the cup like Bowman’s capsule. It receives blood from renal artery which brings excretory wastes from the body to the kidney. It filters water, salts, glucose, urea, the nitrogen-containing end products of proteins and yellow bile compounds from the liver.
15. Why is it essential to match the blood groups of donors and receiver person before arranging transfusion of blood.
Ans. Red Blood Corpuscles of blood carries antigen as well as antibody. If blood is not matched before transfusion then blood of receiver start producing antibodies against donor blood and destroys blood cells, this causes deficiency of blood and causes death.