1. Which one of the following atmospheric layers absorb ultraviolet rays of the sun? (1)
(a) Troposphere
(b) Stratosphere
(c) Ionosphere
(d) Ozonosphere
2.Water potential remains lowest in (4)
(a) Water plants
(b) Woody plants
(c) Succulents
(d) Halophytes
3. The free living bacterium in the soil which increases the yield of rice is (4)
(a) Rhizobium
(b) Azotobacter
(c) Acetobacter
(d) Anabaena
4. The human body’s largest blood vessel is (1)
(a) Pulmonary artery
(b) Aorta
(c) Renal artery
(d) Coronary artery
5. In human body, which one of the following hormones regulates blood calcium phosphate? (3)
(a) Glucagon
(b) Growth hormone
(c) Parathyroid hormone
(d) Thyroxine
