A horizontal force of 10 N is necessary to just hold a block stationary against a wall. The coefficient of friction between the block and the wall is 0.2. The weight of the block is-
(a) 20 N
(b) 50 N
(c) 100 N
(d) 2 N
Compare the functioning of alveoli in the lungs and nephrons in the kidneys with respect to their structure and functioning.
What are the differences between aerobic and anaerobic respiration? Name some organisms that use the anaerobic mode of respiration.
What are the necessary conditions for autotrophic nutrition and what are its by- products?