Question

Number of Barr Bodies in XXXX female is
A. 1
B. 2
C. 3
D. 4

Answer 1

Hint: The barr bodies are the inactive X chromosome with more than one X chromosome and these are one less than the total number of X chromosomes present in the given figure.

Complete answer:
To solve this question you should know what barr body is. The Barr Body is a small structure in cell nuclei of females. The barr body consists of an inactive X chromosome in a cell with more than one X chromosome. So we can say someone with two X chromosomes have one barr body, for example, females chromosomes are XX therefore they have one barr body whereas someone with one X chromosome have no barr body, for example, male have XY chromosomes and hence there is presence of no barr body in males.
The barr body is calculated as one less than the total number of X chromosomes present. If we calculate the barr body in the female which has XX chromosomes, the barr body will be one. If we calculate the barr 's body in males, males have XY chromosomes so the barr body will be zero in males.
In the question, the barr body of XXXX female is asked which means this female has four X chromosomes therefore the barr body will be one less than the total number of chromosomes present. The total number of chromosomes present are four so the barr body will be three. Therefore, the number of barr bodies in the XXXX female is 3.

Thus, the correct answer is option C i.e., 3.

Note:The barr bodies are regarded as diagnostic of genetic femaleness. The inactive chromosome can be seen under the microscope which is seen as shapeless, dark stained, called Barr body. As per the question, females with XXXX chromosomes have 3 barr bodies clearly.