Question

11. A normal chromosome and its homolog carrying an inversion are given below (Y* = centromere) Normal: ABCDEFGH Inversion: a dcbe*fgh Answer the following questions about these homologs (8 points total)

Answer 1

Answer :

Gene flow cannot occur between these 2 populations.

Here inversion is for BCD segment.

If we consider * as centromere

This inversion is paracentric.

So the inversion fragment will be without a centromere, that is acentric.

In anaphase the inversion fragment being acentric, it cannot align or move, and usually its lost. Result in chromosomes with terminal deletions. So the gametes fuse to form zygotes which are inviable. So a crossover event resulting in lethal product.

GENE FLOW

Also known as gene migration or allele flow.

This is the transfer of genetic variation from one population to another. If gene flow is high enough it will form a single population.

If gene flow doesn't occur they in time evolve into 2 different species. Barriers of gene flow can be physical, reproductive or chromosomal.