Biology Questions and Answers
- What is consanguineal
marriage? Why is the
appearing of genetic disease
more probable in the offspring
of a consanguineal marriage?
Consanguineal marriagbetween relatives, i.e., e is the marriagpeople having e
common near ancestors.
The consanthe probability of recessive geguineal marriage increasnetic es
disease in common for people from the samthe offspring since it is (^) e
genetic lineage to be heterozygous
carriers orecessive gef alleles that conditionnetic diseases.
- How is the early diagnosis
of genetic diseases usually
done?
Genetic disease the prenatal period by karyotypmay be diagnosed ine
analysis,DNA analysis, in case o in case f aneuploidiof other diseases.es, or by
The test is performed by removal omaterial containing cells of the embryof (^)
by amniocentesis (extraction of amniotic
fluid) or cordocentesis (puncture oumbilical cord) or even by chorionicf the
villus biopsy (that can be done earlier in
gestation).
Ultrasonography is a diagnostic
procedure for some that produce morphological variationsgenetic diseases (^)
during the embryonic development. Thestudy of genetic family trees is also an
important auxiliary method in the early
diagnosis of many genetic diseases.
The Hardy-
Weinberg Principle
- What is allele frequency?
Allele frequency is the percentage ofappearances of an allele in the
genotypes of a given population
(compared to thstudied gene). e other alleles of the
For examplthere are three alleles (e, in the ABO blood systemI
Considering a group of three persons,A, IB and i).^
one with geother ii, the frequency onotype IAi, other If the allele AIB andI
this “population” is 2/6, the frequencyA in
of the allele of the allele Ii is 3/6.B is 1/6 and the frequency - What is genetic
equilibrium?
Genetic equilibrium is the result of the
Hardy-Weinberg law, a paffirms that under specific conditionsrinciple that (^)
the frequencies of the alleles of a gene
in a given population remain constant.
(The Hardy-Weinberg principle is not
valid in the following populations too small, in tconditions: he occurforrence (^)
of noncasual (driven) crossings, for
populationsmembers and in case of action of with many infertile (^)
evolutionary factors, like natural
selection, mutations and migrations.)
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