Translocated chromosomes

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basophilic

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Say you have a normal individual with two copies of chromosome A and two of chromosome B.
Now say there's a (Robertsonian) translocation to make a hybrid chromosome AB; due to this event, you are now left with one copy of chromosome A, one copy of chromosome B, and the hybrid chromosome AB.
KA says that this individual will now be able to make 6 different types of gametes (A, B, AB, A/AB, A/B, B/AB). This means the three types of chromosomes can synapse and assort however they want during meiosis. Is that true? In other words, the translocation removes the restriction of homologous arrangement in meiosis.

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old post! But would enjoy discussing with anyone who has done this passage :)

https://www.khanacademy.org/test-pr...practice-tut/e/translocations-in-the-germline

Just did it... and failed. Why did the male create 6 possible gametes, not 8? Wouldn't the joint p-arms be a possible gamete also?

For the question that says "Which of the following is not a potential negative effect of a translocation?"

Uhh...a copy of chromosome 21 is missing. Doesn't that show a negative effect?
 
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In the passage they state the small p arms join, but I'm not sure why they don't join them in the question.

For that question- I also misinterpreted it first. It's worded poorly. It's saying: "Which of these bad things can NOT occur from translocation?"

For the father with 1 chromosome 21 and a translocated chromosome 14, do you know what happens during meiosis? Does 21 try to pair with part of its homolog on 14?
 
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In the passage they state the small p arms join, but I'm not sure why they don't join them in the question.

For that question- I also misinterpreted it first. It's worded poorly. It's saying: "Which of these bad things can NOT occur from translocation?"

For the father with 1 chromosome 21 and a translocated chromosome 14, do you know what happens during meiosis? Does 21 try to pair with part of its homolog on 14?
I can see normal 21 trying to pair with the 14 that contains the translocated 21... I just cant see how the normal 21 will try to pair the normal 14 tho...
 
for future readers: The assumption that KA is making is that the translocated chromosome 14/21 aligns with either 14 or 21 during meiosis 1. (This should be stated in the question). As a result 8 gametes form, but 2 are repeats so 6 unique gametes are possible.

Merp.
 
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