3-strand double crossover

[MedPR]

Confused about how this works.

If two of the chromatids crossover normally, you get 2/4 recombinant. The 3-strand double crossover results when one of the newly recombinant chromatids crosses over with one of the non-recombinant chromatids. Somehow this results in only 2/4 recombinant, rather than 3/4 recombinant.

How?

Nevermind.

I forgot that there are 2 sets of identical chromatids. In case anyone had the same question, here's the answer.

---

Members don't see this ad.

 

[mcloaf]

This is so far beyond what you need to know for the MCAT...

 

[MedPR]

This is so far beyond what you need to know for the MCAT...

Genetic recombination and meiosis aren't on MCAT? I read about it on mcat-review so I figured it was relevent.

 

[mcloaf]

Genetic recombination and meiosis aren't on MCAT? I read about it on mcat-review so I figured it was relevent.

Well, there's a difference between knowing the general concepts of meiosis and how/when it results in genetic recombination vs. worrying about the mechanics of a 3-strand double crossover.

 

[MedPR]

Well, there's a difference between knowing the general concepts of meiosis and how/when it results in genetic recombination vs. worrying about the mechanics of a 3-strand double crossover.

Yea I see your point. I didn't learn much in my genetics class so I don't know what is a fundamental concept and what is a more complex topic. When I saw it on mcat-review I figured it was something we were expected to know.

 

[cerium]

Yea I see your point. I didn't learn much in my genetics class so I don't know what is a fundamental concept and what is a more complex topic. When I saw it on mcat-review I figured it was something we were expected to know.

The AAMC lists double crossovers as a topic they expect you to know.