on meiosis...

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junbumkim
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on meiosis...

Post by junbumkim » Wed Apr 25, 2007 2:02 pm

in meiosis a diploid cell divides into 4 haploid cells, which means there is 23 chromosomes in each cell.

Among 4 cells, half of them are from one parent and the rest for the other parent. One of these cells is going to be randomly picked and will ferterlize with another sex cell from a spouse.

Say I have parents of which one has blue eyes and the other has brown eyes. So there were 50% chance that I could have blue eyes or brown eyes. Do I still carry genetic possibility of giving MY child either brown or blue eyes?

Darby
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Post by Darby » Wed Apr 25, 2007 2:39 pm

Your 50% is wrong right from the start (it could be right, but you would need more specific knowledge than what you're using).

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Poison
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Post by Poison » Wed Apr 25, 2007 2:59 pm

Eye color is not a good example for this as multiple modificator genes also play role but I'll try to explain in simple words.
Blue (b) is recessive and brown (B) is dominant.
bb will give a pheotype of blue. BB and Bb will give brown.
So, possibilities:
if bb and Bb is crossed:
1/2 bb you will have blue
1/2 Bb you will have brown
if bb and BB is crossed:
all Bb you will have brown

if your phenotype is blue you will give your children only b. but if you are Bb both are possible.

PS: Half of this is a hypothetic situation. Heredity of eye color is not this simple. In real, parents who both have blue eyes can have children with brown eyes.
It matters not how strait the gate
How charged with punishment the scroll
I am the Master of my fate
I am the Captain of my soul.

junbumkim
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Post by junbumkim » Thu Apr 26, 2007 12:38 am

Darby, would you tell me what part of my understanding is wrong?

I guess I want to know how genetic information from the parents are shared in the offspring's haploid cells

So let's say father is Bb and my mother was bb.

How would this information be distributed among haploid cells?
Would half of haploid cells have Bb, and the rest bb?

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Poison
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Post by Poison » Sat Apr 28, 2007 8:45 pm

Haploid=n
Diploid=2n

As I said before,
mother's gamet= b
Father's gamets= B or b
Cross them. (I did it for you above, have a look at it)
It matters not how strait the gate
How charged with punishment the scroll
I am the Master of my fate
I am the Captain of my soul.

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Poison
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Post by Poison » Sat Apr 28, 2007 8:48 pm

have a look at this figure. I don't think you really know meiosis.
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meiosis.jpg
It matters not how strait the gate
How charged with punishment the scroll
I am the Master of my fate
I am the Captain of my soul.

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