Basic Genetics Help

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

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mikemd
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Basic Genetics Help

Post by mikemd » Sat Feb 20, 2010 8:45 pm

I just have a few question

Are the X and Y chromosomes homologus? but don't they carry different genes?

Genes that are closer together are less likely to recombinate so lower RF and more deviated from medel's law of independent assortment.

If there is a trihybrid cross A/a ;Bb; Cc and B and C are linked genes, how would I go about estimating the Rf of this?

In the book, they say that crossing over is a break at 2 ends and the ends swap places. Is it possible for the middle of a gene to break and swap with another piece (on a 5 gene chromosome)

Thank you so much!

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JackBean
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Post by JackBean » Sat Feb 20, 2010 9:36 pm

you should take A as one and BC/bc as other allele/gene

there are two types of crossing overs. You can either change only middle of the chromosome or the whole end
http://sflc.net/blogs/felbagunu/files/2 ... _large.jpg

Of course, the crossing over could take place in the middle of the gene
http://www.biolib.cz/en/main/

Cis or trans? That's what matters.

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jwalin
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Post by jwalin » Mon Feb 22, 2010 4:17 am

are X and X homologous

so even X and Y should be

another thing they must be so for proper meotic division and for reproduction



and its said that the Y chromosomes was originally a Y but then it disintegrated and it only lacks a few genes many are the same as on X. they ack genes for uterus...
it isn't what you do that matters but it is how you do it

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