Chlorophyll is required in leaves for

1. splitting of water in hydrogen and oxygen
2. trapping sunlight
3. storing food
4. emitting light

The first heart sound (Lubb) is produced due to

1. closure of tricuspid and bicuspid valves
2. closure of aortic and pulmonary valves
3. rushing of blood through valves producing turbulence
4. entry of blood into auricles

Assertion (A) An average adult have about 5-6 litres of blood by volume in his body.

Reason (R) The main functions of the blood in our body are transportation and protection.

1. Both A and R are true
2. Both A and R are false
3. A is true and R is false
4. A is false and R is true

Main reason for sharp rise in world human population in the recent past

1. Poor health care
2. Improved nutrition
3. More deaths
4. Small scale immunisation