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Biology question chromosomes

Hi, please could i have help on this question. I don’t understand why A is incorrect, I know the answer is d but is an incorrect because the chromatids dont have linear dna but it is coiled instead?
Here is the question: https://app.gemoo.com/share/image-annotation/630114727612502016?codeId=DWlz7OL2elleQ&origin=imageurlgenerator

Thanks!
Original post by anonymous294
Hi, please could i have help on this question. I don’t understand why A is incorrect, I know the answer is d but is an incorrect because the chromatids dont have linear dna but it is coiled instead?
Here is the question: https://app.gemoo.com/share/image-annotation/630114727612502016?codeId=DWlz7OL2elleQ&origin=imageurlgenerator
Thanks!

Its interphase, not after semi conservative replication.
Before replication, 1 chromosome has 1 chromatid.
After replication, 1 chromosome is 2 chromatids joined at centromere.
Reply 2
Original post by BankaiGintoki
Its interphase, not after semi conservative replication.
Before replication, 1 chromosome has 1 chromatid.
After replication, 1 chromosome is 2 chromatids joined at centromere.

Aren’t there always 2 chromatids in a chromosome?
Original post by anonymous294
Aren’t there always 2 chromatids in a chromosome?

No - you only think it is that way, because chromosomes become visible during mitosis.
Mitosis happens after semi-conservative replication.
Original post by BankaiGintoki
No - you only think it is that way, because chromosomes become visible during mitosis.
Mitosis happens after semi-conservative replication.

Ohhh, so during interphase, is it visible as chromatin?
Original post by anonymous294
Ohhh, so during interphase, is it visible as chromatin?


In interphase the chromosomes are unfolded, so a state in which they are not coiled. That is the phase in which chromatins are still in existence, but in the next one, the prophase, the chromatins start to get coiled by histons to chromatid first, then to a chromosome step by step. In short: yes, you would see it in interphase.
(edited 1 month ago)
Original post by Kallisto
In interphase the chromosomes are unfolded, so a state in which they are not coiled. That is the phase in which chromatins are still in existence, but in the next one, the prophase, the chromatins start to get coiled by histons to chromatid first, then to a chromosome step by step. In short: yes, you would see it in interphase.

Ohh thanks :smile:
Original post by anonymous294
Ohh thanks :smile:


You are welcome. But if you ask me how to see the chromatin in interphase with what devices exactly, I have no clue.

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