polar body

[Jordwin]

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I am taking a Kaplan class and they said there are only 2 polar bodies, but I've learned before that 3 polar bodies exist. Which is true?

 

[hope_to_match]

this is from cliff's : "at the end of meiosis 1, one daughter cell is the secondary oocyte containing most of the cytoplasm & the other daughter cell is a polar body with very little cytoplasm. the polar body may continue with meiosis 2 and divide into 2 daughter polar bodies ..."

i believe i saw a question in destroyer which also said it's 3 polar bodies ( one from meiosis 1 and the other two from meiosis 2)

 

[Jordwin]

Yeah that's what I was thinking too. Ill just assume 3 is correct. Thanks!

 

[hope_to_match]

🙂

 

[gn4]

I guess it depends on How they ask the question.... if they ask How many there are at the end of meiosis 2, wouldn't you say 2 polar bodies?

 

[hope_to_match]

I guess it depends on How they ask the question.... if they ask How many there are at the end of meiosis 2, wouldn't you say 2 polar bodies?

hmmm i think that even if they ask how many at the end of M-2 it is still 3

the first one is from M-1 when the primary oocyte divides into 1 polar body and 1 secondary oocyte. then... in M-2 secondary oocyte divides into an egg and one polar body and also during M-2 the polar body that was formed in M-1 also divides and undergoes M-2 forming 2 extra polar bodies. So at the end of M-2 women have 3 total polar bodies.

soo...i think if they ask how many are produced DURING M-2 the answer is 3. If they ask how many are there at the end of M-2 the answer is still 3

 

[hope_to_match]

http://www.youtube.com/watch?v=uXN0gVfc4gM

this is a good video..basically 2 polar bodies MAY BE produced from the polar body that was formed in M-1 (given that it undergoes M-2, but it might not) and 1 polar body is produced from the secondary oocyte. That's why there is confusion and different books explain it differently but i do remember this now that I watched the video

Also, I think this google image does a good job showing the production of polar bodies: http://www.google.com/imgres?imgurl...dxmAWnppuDd1M:;Ml6MPCTfGuuBVM;ddxmAWnppuDd1M:

 

[Jordwin]

Ah okay so the first polar body might not go through meiosis 2. That's the discrepancy.

 

[hope_to_match]

Ah okay so the first polar body might not go through meiosis 2. That's the discrepancy.

yup some books say it some say it doesn't some say it may

 

[gn4]

ah ok. Thank you for the explanation.

 

[hope_to_match]

ah ok. Thank you for the explanation.

no problem i looked back at cliffs and KBB they don't do a good job describing this at all

 

[sakthivs]

So let me get this clear. When the primary oocyte finishes meiosis 1 it produces the secondary oocyte along with a polar body (this polar body can continue with meiosis 2 but the two daughter cells disintegrate). Then later during fertilization when the secondary oocyte finishes meiosis 2 it produces an egg and another polar body? can this other polar body also undergo meiosis 2 or does it just disintegrate right away?

 

[hope_to_match]

So let me get this clear. When the primary oocyte finishes meiosis 1 it produces the secondary oocyte along with a polar body (this polar body can continue with meiosis 2 but the two daughter cells disintegrate). Then later during fertilization when the secondary oocyte finishes meiosis 2 it produces an egg and another polar body? can this other polar body also undergo meiosis 2 or does it just disintegrate right away?

No i dont believe it can. Polar bodies is a way to get rid of genetic material that the zygote won't need (hence- an egg gets most cytoplasm and polar bodies get few if any) . Polar bodies eventually undergo apoptosis. Sometimes polar bodies may participate in life cycle of an organism but I am sure that's beyond the scope of what we need to know for this test.