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A level Biology: Post your doubts here!

S

Shemyaa

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Clark20 said:
Need help understanding this. Why is the answer not B? As the chromosome does condense during prophase. (The correct answer is D).
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Hi there! I hope I am not late
One thing I want to say, biology mch examiners are so good at playing with words. As you concentrate more on what they're saying you'll realize its much easier than you thought.
Let me break this down,
Why its not B: First, its the DNA that coils around histone proteins therefore them using the phrase" come close together is wrong" and one thing too is when chromosomes condense we mean each chromatid condenses, therefore, the DNA further condenses to form a condensed form and not the chromosome itself (chromosomes is a terminology that is used instead of sister chromatids that's why if you realized in the ms they interchange them a lot"
Why it's not C: Even though C is 100% correct, the only difference is that the question wants what happens in prophase and what happens in C is what needs to happen during interphase so doesn't apply to the qsn.
Why it's D: Because they the DNA coils around histone proteins and they further coil and twist to form a chromatid. Also, its as if the dark circle is holding each knot of the coiling part so how can we say that the chromosome further coils around it?
I hope I made some sense
 
C

Clark20

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Shemyaa said:
Why it's D: Because they the DNA coils around histone proteins and they further coil and twist to form a chromatid. Also, its as if the dark circle is holding each knot of the coiling part so how can we say that the chromosome further coils around it?
I hope I made some sense
Click to expand...

I now understand why A, B and C are wrong. Can you please once more explain why D js correct? Shouldnt the option say "form strands that fold and twist together to from a chromosome"? Or is their wording the same? Are chromosomes and chromatids the same thing? Individual chromatids are coiled and thick too?
 
C

Clark20

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Need help understanding this one too. Stuck between option A and C.
 

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