Please explain this Question

[navneetdh]

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cliffs ap bio--pg 82--question 2

If a cell has 46 chromosomes at the beginning of meiosis, then at anaphase I there would be a total of

a. 23 chromatids
b. 23 chromosomes
c. 46 chromosomes
d. 46 chromatids
e. 92 chromosomes

ANSWER IS C.

reason given---during metaphase I, homologous chromosomes pair at the metaphase plate. One member of each pair migrates to opposite poles during anaphase II, so the total is still 46 chromosomes.


I have no clue wth they are saying. Not even once the answer said anaphase I. WTF

Here is what I thought----46=2n so finally it has to be n=23
after meiosis 1 it becomes n=23 and meiosis 2 maintains it at 23 chromosomes.

So I thought answer is B.

 

[BiomajorPreDent]

I got C just by doing process of elimination

Now, someone will have to correct me if my reasoning is wrong, but
even though there are 23 chromosomes on each side of the cell in anaphase 1 its still one big cell, (no cleavage yet) so there would still be 46 chromosomes overall.

I wrote the explanations out of my cliffs book:

"During metaphase 1, homologous chromosomes pair at the metaphase plate. One member of each pair migrates to opposite poles during anaphase 1. If the cell started with 46 chromosomes, 23 chromosomes move to each pole during anaphase 2, so the total is still 46 chromosomes"

I see what youre saying..it is kinda confusing. I dont understand the explanation completely either, maybe its a typo or someone else can shed some light on the wording.

 

[prsndwg]

cliffs ap bio--pg 82--question 2

If a cell has 46 chromosomes at the beginning of meiosis, then at anaphase I there would be a total of

a. 23 chromatids
b. 23 chromosomes
c. 46 chromosomes
d. 46 chromatids
e. 92 chromosomes

ANSWER IS C.

reason given---during metaphase I, homologous chromosomes pair at the metaphase plate. One member of each pair migrates to opposite poles during anaphase II, so the total is still 46 chromosomes.




I have no clue wth they are saying. Not even once the answer said anaphase I. WTF

Here is what I thought----46=2n so finally it has to be n=23
after meiosis 1 it becomes n=23 and meiosis 2 maintains it at 23 chromosomes.

So I thought answer is B.

at the end of anaphase I, the cell still has not yet cleaved and its one.. so the number of chromosomes stays the same.. it could also be 92 chromotids.. every 2 chromotids makes one chromosome

 

[BiomajorPreDent]

at the end of anaphase I, the cell still has not yet cleaved and its one.. so the number of chromosomes stays the same.. it could also be 92 chromotids.. every 2 chromotids makes one chromosome

Yeah, I am glad my reasoning is sound. 🙂

 

[vlct0ria]

cliffs ap bio--pg 82--question 2

If a cell has 46 chromosomes at the beginning of meiosis, then at anaphase I there would be a total of

a. 23 chromatids
b. 23 chromosomes
c. 46 chromosomes
d. 46 chromatids
e. 92 chromosomes

ANSWER IS C.

reason given---during metaphase I, homologous chromosomes pair at the metaphase plate. One member of each pair migrates to opposite poles during anaphase II, so the total is still 46 chromosomes.


I have no clue wth they are saying. Not even once the answer said anaphase I. WTF

Here is what I thought----46=2n so finally it has to be n=23
after meiosis 1 it becomes n=23 and meiosis 2 maintains it at 23 chromosomes.

So I thought answer is B.

In metaphase I, the 23 sets of homologues (46 c'somes total) pair at the metaphase plate...by anaphase I, one of each set of homologous pairs is beginning to move toward opposite poles...there is still only the one cell you began with since Meiosis I isn't over yet, so you still have the 46 total c'somes (23 near each pole).

 

[UCB05]

cliffs ap bio--pg 82--question 2

Here is what I thought----46=2n so finally it has to be n=23
after meiosis 1 it becomes n=23 and meiosis 2 maintains it at 23 chromosomes.

So I thought answer is B.

*edit* bah, someone already got to it 😛

 

[navneetdh]

Ok I think I get it now---anaphase I the cell is still together---as a blob---so this blob still has 46 choromosomes and not just 23.

Thanks. The reasoning in cliffs was weirrrdd.

Thanks all of you 😀👍