. Write notes on
(a) Adam’s apple.
(b) Secondary sexual characters.
(c) Sex determination in the unborn baby.
a) Adam’s apple: In human males, the larynx grows larger at the time of puberty and can be seen as a protruding part of the throat. This protrusion is known as Adam’s apple. In boys under the influence of sex hormones, the larynx becomes prominent. Due to this, the vocal cord becomes thicker and longer which causes the voice hoarse. On the other hand in females, the larynx is of small size and is hardly visible. Therefore, girls have a high pitched voice while the boys have a deep voice.
b) Secondary sexual characters: Characters which usually appear during the phase of puberty are called as secondary sexual characters. These are the features that help in distinguishing the male and female body from each other.
Characters seen in male: Hoarseness of voice, appearance of beard, broadness of chest, growth of hair in genital areas.
Characters seen in female: Start of menstrual cycle, growth of breast, growth of hair in the genital areas.\
c) Sex determination in the unborn baby: Sex of a unborn baby depends upon the pair of sex chromosomes that are present in the cells of the baby.
X and Y chromosomes are the sex chromosomes in humans. Ovum always contain X chromosome, male sperm may carry either X chromosome or Y chromosome. Male genetic make-up is 44 autosomes + XY chromosome and female genetic make-up is 44 autosomes + XX chromoses.