are sister chromatid exchange effective in producing variabi

are sister chromatid exchange effective in producing variability in an individual? in the offspring of individual?

can you explain it to me?

Solution

The human genome, along with other diploid organisms contains homologous chromosomes with sister chromatids. These sister chromatids are technically a pair of chromosomal arms arising from the centromere. For a homologous pair of chromosome, both of these chromosome comprise of sister chromatids attached at the centromere.

The biological relavance of these sister chromatids can be understood in terms of recombination. These sister chromatids contain linearly arranged genes on them which represent a physical trait for the individual. When a diploid cell divides by meiosis, the homologous chromosomes proximate each other in a way that theri sister chromatids lie side by side to each other in a parallel manner. Since these chromatids are long extensions of the chromosomal arms with centromere as the only point of attachment, they are possessed with large amount of flexibility. Thus, as these chromosomal arms approach each other, they are able to entangle and thus bring about cross-over and recombination. These recombinations between the sister chromatids of homologous chromosomes are responsible for changing the genetic sequences and thus generate variation in the organisms.

Thus, this explains that sister chromatid exchange is improtant and critical event for generating variability among individuals.