Question

An individual who is XXX, but that has been found to have a translocation where the SRY gene is stuck on the end of chromosome 4, would be phenotypically ________ and would have ____ Barr bodies

Answer 1

SRY is a gene found on Y chromosome and it brings male characters in an individual. It produces a protein called sry protein which is also called TDF (testis determining factor). This protein brings the development of testis which is the first step in male development instead of female in an embryo.

If the gene SRY is present on the end of 4th chromosome, it will transcribe TDF which will initiate the development of the testis and the later events will follow towards the development of the male individual. So, the individual will be male. The number of Barr bodies will be 2. This is because any number of X-chromosomes more the 1 will get converted to Barr bodies. Which means only one X - chromosome will be active in an individual.

So, XXX individual in this case will be phenotypically Male and the number of Barr bodies will be --2.