Question

The number of "Barr Bodies" present in a somatic cell of a woman suffering from Turner syndrome is___.

• A. 0
• B. 1
• C. 2
• D. 3

Answer 1

The Correct Option is A

To determine the number of "Barr Bodies" present in a somatic cell of a woman suffering from Turner syndrome, it's essential to understand what Barr Bodies are and the genetic characteristics of Turner syndrome.

Barr Body Explained:

• Barr Bodies are inactivated X chromosomes found in female cells.
• In typical females (46,XX), one of the X chromosomes is inactivated, forming one Barr Body.
• The formula for calculating Barr Bodies is: N - 1, where N is the number of X chromosomes.

Understanding Turner Syndrome:

• Turner syndrome is a chromosomal disorder affecting females, where all or part of one of the X chromosomes is missing or altered.
• It typically presents as having only one X chromosome (45,X).
• Thus, women with Turner syndrome usually have one X chromosome and no additional X chromosome to inactivate.

Calculation of Barr Bodies:

• For an individual with Turner syndrome (45,X), N = 1.
• Therefore, the number of Barr Bodies = 1 - 1 = 0.

Given the above explanation, the number of Barr Bodies present in a somatic cell of a woman suffering from Turner syndrome is 0. This logical deduction aligns with our understanding of chromosome behavior in Turner syndrome.

Option Analysis:

• 0: Correct. Turner syndrome typically presents with a single X chromosome, resulting in zero Barr Bodies.
• 1, 2, 3: Incorrect. These options suggest additional X chromosomes that would form Barr Bodies, which is not typical for Turner syndrome.