A pair of homologous chromosomes in Drosophila has the following content (single letters represent genes):
Chromosome 1 RNMDHBGKWU
Chromosome 2 RNMDHBDHBGKWU
How does the pairing diagrammed in part (b) differ from the pairing of chromosomes in an inversion heterozygote?

Question

A pair of homologous chromosomes in Drosophila has the following content (single letters represent genes):

Chromosome 1 RNMDHBGKWU

Chromosome 2 RNMDHBDHBGKWU

How does the pairing diagrammed in part (b) differ from the pairing of chromosomes in an inversion heterozygote?

Accepted Answer

Hello, everyone and welcome to today's video. So which of the following statements is correct regarding the difference, impairing of homologous chromosomes and inversion heterozygote during crossing over. So as answer choice, A we have homologous chromosomes aligned correctly during crossing over. While in inversion, heterozygote, the inversion loop forms and prevents proper alignment as answer choice B we have the nemo complex is involved in the pairing of homologous chromosomes during crossing over but not impairing during an inversion heterozygote. As answer choice C we have inversion, heterozygote have difficulty aligning their chromosomes during crossing over while homologous chromosomes has no such difficulty. And as answer choice D we have no, there is no difference in the pairing of homologous chromosomes and inversion heterozygote during crossing over. So we know that during crossing over homologous chromosomes are going to align and exchange material. This happens during meiosis. So we know that homologous chromosomes are going to be able to exchange genetic material without any issues. However, we also have this inversion I and what's happening, what's happening with this inversion heterozygote is that we have one chromosome that has a segment that is inverted compared to a homologous chromosome And because of this, this is going to lead to the formation of something called the inversion loop. And this inversion loop during pairing is going to prevent the proper alignment of the homologous chromosome. So this is going to stop crossing over from occurring because of this, the correct answer for this question is going to be answer choice. A homologous Muslims align correctly during crossing over. While in inversion, zygotes, the inversion loops form and prevents proper alignment, right is a final answer to our question. I really hope it's helped and I hope to see you on the next video.

A pair of homologous chromosomes in Drosophila has the following content (single letters represent genes):
Chromosome 1RNMDHBGKWU
Chromosome 2RNMDHBDHBGKWU
How does the pairing diagrammed in part (b) differ from the pairing of chromosomes in an inversion heterozygote?

Verified video answer for a similar problem:

Key Concepts

Homologous Chromosomes

Inversion Heterozygote

Meiotic Pairing