Re: HYB: Punnett Square
- To: Multiple recipients of list <i*@rt66.com>
- Subject: Re: HYB: Punnett Square
- From: L* M* <l*@icx.net>
- Date: Thu, 24 Jul 1997 15:53:12 -0600 (MDT)
> Chad Schroter wrote:
> : If I understood TWOI correctly certain genes could be carried on =
> : separate chromosomes and thus be easy to separate or combine, while
> others may =
> : be located closely together on the same chromosome and be relatively
> difficult =
> : to separate (i.e.. both genes would tend to be present together or
> absent =
> : together)
Sharon McAllister wrote:
> That is correct. Genes that are located on separate chromosomes segregate
> independently. Those that are located closely together on the same
> chromosome are said to be linked. Linkage can be an advantage if you can=
> find a cultivar with the desired alleles linked -- an obstacle if the
> "wrong" ones are linked. The phenomenon that breaks linkages is called
> "cross-over". It happens during meiosis, when members of a pair of
> chromosomes may break and exchange portions. =
Does that happen frequently? Are there some kinds of crosses
(mismatched chromosome pairs maybe?? one parent with damaged chromosomes
and mostly sterile?) that increase the probability of this happening?
Linda Mann
lmann@icx.net
