A diploid organism with a genome size of n = 23 experienced a Robertsonian translocation. How many chromosomes would you expect to see in the karyotype of a somatic cell in an affected individual?

Question

Quizplus · Accepted Answer

Robertsonian translocation involves the fusion of two acrocentric chromosomes at their centromeric regions, effectively reducing the chromosome count by one. Since a diploid organism normally has 2n chromosomes, for a human with n = 23, the normal count is 46. After a Robertsonian translocation, the count would decrease by one, resulting in 45 chromosomes. However, since the question asks about a somatic cell, which is diploid, and considering the translocation as a singular event, the correct interpretation should be that the organism starts with 46 chromosomes (2n for n = 23) and the translocation would not change the overall count in a diploid organism, maintaining it at 46. The explanation provided was incorrect in suggesting a reduction to 45, which would apply to the product of gametes, not somatic cells. The correct answer, reflecting a standard diploid count for a human, should be 46, not 45, acknowledging an error in the initial explanation.

A Diploid Organism with a Genome Size of N =