question_answer 8)

Write notes on : (a) Adam's apple (b) Secondary sexual characters (c) Sex determination in the unborn baby.  

Answer:

(a) At puberty, the voice box or the larynx begins to grow. Boys develop larger voice boxes. The growing voice box in boys can be seen as a protruding part of the throat called Adam's apple.                     (b) Secondary sexual characters are the traits that distinguish the two sexes of an individual. In human beings, secondary sex characters in males include gain in height, a prominent Adam's apple, deep voice, growth of beard, moustaches and pubic hair, hair on the chest, thighs and armpits. In females, the secondary sexual characters are seen as height gain, but with shorter stature than boys, less facial hair growth of pubic hair, hair in  armpits, high-pitched voice, and development of breasts. Other features include broadening of pelvis and deposition of fat around hips and smoother skin texture.   (c) The sex of the unborn baby is determined by the sex chromosome of the father. An unfertilized egg  always has X chromosome. If a sperm contributes X chromosome then the baby will be a female and if the sperm contributes Y chromosome, the baby will be a male. So it is the father, who is responsible for the sex of the unborn baby.