Question

Read the following and answer from given below:

Turner's syndrome is an example of monosomy. It is formed by the union of an allosome-free egg and a normal 'X' containing sperm or a normal egg and an allosome-free sperm. The individual has 2n = 45 chromosomes (44 + X0) instead of 46. Such individuals are sterile females who have rudimentary ovaries, underdeveloped breasts, small uterus, short stature, webbed neck, and abnormal intelligence. They may not menstruate or ovulate. This disorder can be treated by giving female sex hormones to women from the age of puberty to make them develop breasts and have menstruation. This makes them feel more normal.

The number of Barr bodies present in a female with Turner's syndrome is ______

Options

• 0

• 1

• 2

• <2

Answer 1

The number of Barr bodies present in a female with Turner's syndrome is 0.

Explanation:

Barr body is a structure consisting of a condensed X chromosome that is found in non-dividing nuclei of female mammals. The presence of Barr's body is used to confirm the sex of athletes in sex determination tests. It is named after the Canadian anatomist M.L., Barr, who identified it. The number of Barr bodies is one less than the total number of X chromosomes. In Turner's syndrome genotype is 45 + X0, so the number of Barr bodies is 0.