Question

A human female with Turner’s syndrome
A) Has an additional X chromosome
B) Exhibits male characters
C) Is able to produce children with a normal husband
D) Has 45 chromosomes with XO

Answer 1

Hint: There are many genetic conditions which involve changes in chromosome number. Aneuploidy refers to a single chromosome being more in number, whereas polyploidy refers to the entire set being more in number.

Complete Answer:
- Turner’s syndrome is typical example of aneuploidy involving the sex chromosomes, specifically the female sex chromosome, X. In this condition, the individual has one X, and is missing a second sex chromosome. Genetically, she is 45 XO. Option D is correct.
- There is another condition which is called triple X syndrome, where the individual has an extra copy of the X chromosome. This does not apply to Turner’s syndrome. Option A is incorrect.
- As the individuals have one copy of the X chromosome, they are considered to be genetically female, and do not exhibit male characters. Option B is incorrect.
- Individuals with Turner’s syndrome typically do mature sexually without external hormonal treatment and are unable to have children. Option C is not correct.
- Turner’s syndrome is not an inherited condition, but is associated with incorrect separation of chromosomes during development of the germ cells. Depending on whether all cells of the individual are 45 XO, or they exhibit mosaicism where some cells of the body are 46 XX and others 45 XO, the extent and severity of the symptoms will differ.

Hence the correct answer is option B.

Note: Besides incomplete or missing female sexual development, individuals with Turner’s syndrome or monosomy X exhibit other signs like neck webbing, short stature, short fingers and toes, and a low hairline.