Question

A human female undergoes a cytogenetic test and it is found that the cells each contain one Barr body. The best conclusion that can be made from this observation is

a) this is typical of human genetically female cells

b) this is a genetic female with Kleinfelter Syndrome

c) This is a genetic female with Turner Syndrome

d) this is a genetic female with no active X chromosome

Answer 1

The correct answer is. "A" this is a typical of human genetically female cells.

• Because females have 2 XX chromosomes as sex chromosomes and one of the two X chromosome in each cell is usually inactive by the process of lyonization this occures because females will produce twice as much of gene product of X chromosome and this is waste of protein.

B is incorrect because kleinfelter syndrome occures in male where they have one extra X chromosome

C is incorrect because in Turner syndrome there is absence of one X chromosome but in this situation there is barr body (inactive X chromosome) present.

D is incorrect because it says there is no active X chromosome present but that's not true in cytogenetic test we found one barr body which means another one is active X chromosome.