Biology Questions and Answers

(Greg DeLong) #1

Biology Questions and Answers


The Mendel’s first law is also known as


the law odeduced the way gf purity of enes and alleles weregametes. Mendel (^)
transmitted and traits were conditioned
without even knowing of the existencof these elements. e



  1. Which is the type of gamete
    (for a given trait) produced by
    a dominant homozygous
    individual? What is the
    genotypical proportion of
    these gametes? What about a
    recessive homozygous
    individual?


If an individual homozygous, for example, AA, itis dominant (^) will
produce oA. The proportion thnly gametes hus is 100% of AAaving the allele
gametes.
If an individual homozygous, for example, aa, it willis recessive (^)
produce oa, also in a 100% proportion.nly gametes having the allele



  1. Which is the type of
    gamete produced by a
    heterozygous individual?
    What is the genotypical
    proportion of these gametes?


Heterozygous individuals, for example,


AA, produce two gametes: one containindifferent typg the allele es of (^) A
and another type containing the allele a.
The proportion is 1:1.



  1. In the F2 generation of a
    hybridization for a given trait
    conditioned by a pair of alleles
    T and t, according to Mendel’s
    first law what are the
    genotypes of each
    phenotypical form? How many
    respectively are the
    genotypical and phenotypical
    forms?


In the mentiogenotypical forms in ned hybridization F2 will be TT, ttthe (^)
and Tt. Therefore there will be three
different genotypical fdifferent phenotypical formsorms and two
(considering T dominant over t).



  1. Why can the crossing of an
    individual that manifests
    dominant phenotype with
    another that manifests
    recessive phenotype (for the
    same trait) determine
    whether the dominant
    individual is homozygous or
    heterozygous?
    From the crossing ofhaving recessive phenotype with an individual
    another the same having dominant ptrait) it is possible tohenotype (for
    determine whether the dominant


individual heterozygous. This is truis homozygous ore because (^) the
genotype of the recessive individual is
obligatorily hoaa. If the other individual is alsomozygous, for example,
homozygous, AA, the F1 offspring will
be only heterozygous (aa x AA = Aa). If the other individual is only
http://www.biology-questions-and-answers.com

Free download pdf