a) Reproductive life of a woman lasts from menarche to menopause.

The first menstrual flow begins at puberty around the age of 10 – 12 years in girls known as menarche. Because at this age ovaries start producing eggs indicating the starting of reproductive age. At the age of 45 – 50 years menstrual cycle stops as ovary lose the ability to produce eggs which marks the end of reproductive phase known as menopause.

b) The development of a caterpillar to an adult butterfly is termed as metamorphosis.

Metamorphosis is the process in which larvae enters various stages to develop into an adult. This process is regulated by insect hormones. The larvae/caterpillar enters into pupa stage then finally become a butterfly.

c) The overgrowth of muscles in larynx leads to the hoarse voice in adolescent boys.

During puberty, in boys, the muscles present in voice box grows and this can be seen as a protruding part of the throat known as Adam’s apple. Due to this boys develop a deep, hoarse voice.

d) Adrenaline helps the body to adjust and fight the stress.

Adrenaline is called stress hormone which is secreted from adrenal glands at the time of stress. It helps the body to face the emergency situation or flight away from it.