Genetics as it applies to evolution, molecular biology, and medical aspects.

yahoo12345
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Consider the following example. If on the same chromosome: (a) there was 5% crossing over between genes A and B, 7% crossing over between A and C and 12% crossing over between B and C, draw a section of the chromosome showing the location and map distance apart for the genes A, B and C (b) the percentage crossing over between B and C was not 12% but 2%, draw a section of the chromosome showing the location and map distances apart for the genes A, B and C.

That's the question, but I'm not really sure how to do it. Can someone demonstrate it or any photos?? Please help me. Thanks.

canalon
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1 centi morgan: distance between 2 genes who will lead to 1% recombination.
You know the percentage of recombination, so you know the distance between A and B, A and C, and B and C, and it should not be too complicated to draw maps for both situation, it is just pure logic.
Patrick

Science has proof without any certainty. Creationists have certainty without
any proof. (Ashley Montague)

yahoo12345
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can u please give me a sample to solve the first one?..because it's a lesson my teacher never taught..thanks..HOW COULD I "DRAW A SECTION IN A CHROMOSOME TO DETERMINE THEIR LOCATION..."? PLEASE HELP!

canalon
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Draw a line, that is your section of chromosome. Put a mark on it, and name it A. Arbitrarily (and conveniently) define a scale for genetic distance (1 centimorgan= 1centimeter/square/whatever).
Then write on a paper the distances between A and B, A and C, and B and C.
See which locations for the 3 points will match with our measurements (not too hard) and repeat for the second set of distances.
Patrick

Science has proof without any certainty. Creationists have certainty without
any proof. (Ashley Montague)

yahoo12345
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sir what about the thing they called "map unit"? is it same as centi morgan?

canalon
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never heard that, but I would suppose so.
Patrick

Science has proof without any certainty. Creationists have certainty without
any proof. (Ashley Montague)

siroma
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yahoo12345 wrote:sir what about the thing they called "map unit"? is it same as centi morgan?

That's right.
http://en.wikipedia.org/wiki/Centimorgan

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