If a potted plant is kept horizontally for a few days,in which direction does the tender stem of the plant grow?

Name the sensory receptors found in the nose and on the tongue.

What are reflex actions? Give two examples. Explain a reflex arc.

What are voluntary and involuntary actions? Give one example of each.

In which lobe of the cerebrum are the auditory and olfactory centers located?

$(a)$ Define hormone. Write four characteristics of hormones in humans.
$(b)$ Name the disorder caused by the following situations:
$(i)$ Under secretion of growth hormone
$(ii)$ Over secretion of growth hormone
$(iii)$ Under secretion of insulin
$(iv)$ Deficiency of iodine