Biology Questions and Answers

(Greg DeLong) #1

Biology Questions and Answers


located in the other side, they will be
separated be formed, instead oand gametes A-B anf A-b and a-B.d a-b will


(The percentage of recombigametes relating to normal gnantametes (^)
depends upon the crossing over rate
that in distant the given alleles arits turn depends upon how fare in the
chromosome.)



  1. In genetic recombination by
    crossing over what is the
    difference between parental
    gametes and recombinant
    gametes?


Parental gametes are those gthat maintain the original linkage ametesof
genes (allelRecombinant ges) in the chromosome.ametes are those in
which the original linkage is undone due
to exchange of chromosomal pcrossing over during meiosis. ieces by



  1. What is recombination
    frequency?


Recomover rate, bination fis the percentagrequency, or e ofcrossing
recombinaover (in relation nt gametes madto the number ofe by crossing
parental gametes made). It always
refers to two gchromosome. enes located in the same



  1. Why does the
    recombination frequency of
    genes vary with the distance
    between them in the
    chromosome?


The farther the distance bloci of two genes in a chrometween theosome the (^)
higher the recombination frequency
between these genes. This is trubecause once alleles are nearer in thee (^)
chromosome it is more probable that
they are kept united when chromosomalextremities are exchanged by crossing
over. On the other hand, if they are
farther apart itseparate by crossing o will be easier ver. for them to



  1. What is a centimorgan?
    Centimorgan, or recombination unit, by


conventiolinked genes that corresponds to n is a distance between two1% of (^)
recombination frequency of these
genes.



  1. How can the concept of
    recombination frequency be
    used in genetic mapping?
    Genetic mapping is the determination othe location of the genes in a f
    chromosome.


By determining the recombinationfrequency between several different (^)
linked genes it is pthe distance between them in theossible to estimate
chromosome. For example, if a gene A
has a recombination fwith the gene B, this gene B hasrequency o f 20%
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