CELL DIVISION
MEIOSIS AND GENETIC VARIATION
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
It is an inactivated Y chromosome and results in a man being sterile.
|
|
|
It is an inactivated Y chromosome and the person who has it appears phenotypically female.
|
|
|
It is an inactivated X chromosome and results in females with half their cells having one X inactivated and the other half of their cells having the other X inactivated.
|
|
|
It is an inactivated X chromosome and results in females who are sterile.
|
Detailed explanation-1: -Barr body can be easily identified with ordinary stains. It also helps in identifying the sex of an individual when used judiciously. A review is made on the lyonization of Barr body and its utility in sex determination.
Detailed explanation-2: -Which of the following statements best describes what a Barr body is and its significance? It is an inactivated X chromosome and results in females with half their cells having one X inactivated and the other half of their cells having the other X inactivated.
Detailed explanation-3: -Barr bodies have no function other than to exist in the inactive form to mitigate the gene dosage effects. The presence of a Barr body indicates that the organism has more than one X chromosome, which is the case in females (XX). The pattern of inactivation is different in mammals and marsupials.
Detailed explanation-4: -The barr body is sex chromatin, in which the body has an inactive X chromosome. The barr body is formed due to the inactivation of genes on one of the X chromosomes present in females. It is to prevent the double expression of the X chromosome.