Biology Questions and Answers

(Greg DeLong) #1

Biology Questions and Answers


Non-mendelian


Inheritance



  1. According to Mendel’s law
    phenotypical characteristics
    would be determined by pair
    of factors (alleles) that
    separate independently in
    gametes. What are the main
    types of inheritances that are
    exceptions to Mendel’s rules?


There are many types of inheritance


that do not follow pattern. Notable among them arthe mendeliane: (^)
multiple alleles, gene interactions
(complementary gequantitative, or polygenic, innes, epistasis andheritance (^) ),
linkage with or without crossing over
and sex-linked inheritance.
Pleiotropy, lacking of dominance and
lethal genes do not fit as variations oinheritance since genes can have thesef (^)
behaviors and at the same time omendelian laws. bey
Mutationsabnormalities that also alter th and aneuploidies aree (^)
mendelian pattern of inheritance as well
as mitochomitochondrial DNA fndrial inheritance rom the mother(passage of
through the cytoplasm of the egg cell to
the offspring).



  1. What is the genetic
    condition in which the
    heterozygous individual has
    different phenotype from the
    homozygous individual?


This condition isdominance and it can h called lack ofappen in two (^)
ways: incomplete dominance or
codominance.
In incomplete dominance the
heterozygous presents an intermphenotype between the two types oediatef
homozygous, as in sickle cell anemia in
which the sick red blood cells and some nheterozygous produces somormal e
red blood cells. Codominance occurs, for
example, the MN blood group system, in in the genetic determination which of
the heterozygous has a ptotally different from the homozyhenotypegous, (^)
not being an intermediate form.



  1. What is pleiotropy?
    Pleiotropy (or pliotropy) is the


phenomenon in which a conditions several different phenotypicalsingle gene (^)
traits.
Some phenotypical traits may be
sensitiveexample, to pleiotropic einhibition) of other genes,ffects (for (^)
even when conditioned by a pair of
alleles in simplcases a mixture of pleiotropy e dominance. In theseand gene (^)
interaction is characterized.
http://www.biology-questions-and-answers.com

Free download pdf