Genetics: Recombination (reply asap)

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bigvanessa
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Genetics: Recombination (reply asap)

Post by bigvanessa » Wed Aug 15, 2007 2:28 am

Hello,

I'm totally stuck on my biology questions, I do not know where to start, to be honest.

Here are the questions;

1) Suppose recombinations between alleles A and B in a pair of homologus chromosomes occurs 20% of the gametes in an individual heterozygous for Aa, Bb and Cc, and that it occurs between A and C in 8% of the gametes. How often would you expect recombination between B and C?

2) What types and frequencies of male progeny are expected from the following crosses in Drosophilla?

y = yellow, sn = singed; lz = lozenge (recessives)
+ indicates wild (normal) type

y sn lz x y+ sn+ lz
------- -----------
_ -----------
y sn lz

3) Genes A and B are 10 crossover units apart. What genotypes, and in what proportions, are expected from the cross?

A B A B
---- female x ------ male
---- -------
a b ab


If anyone can help me it would be greatly appreciated!! I'm totally stuck.

Regards,
Vanessa.

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mith
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Post by mith » Wed Aug 15, 2007 4:26 am

Make an attempt and show what you've done so far.
Living one day at a time;
Enjoying one moment at a time;
Accepting hardships as the pathway to peace;
~Niebuhr

bigvanessa
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Attempt of Question (1)

Post by bigvanessa » Wed Aug 15, 2007 6:05 am

O.K. Well I've attempted but I don't know if it is correct or not. I think it's 12% of recombination between B and C ????

Correct me if i'm wrong.

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