GENETICS AND EVOLUTION
GENETIC BASIS OF INHERITANCE
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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The genes associated with the X linked conditions are linked to the X chromosome, which determines maleness.
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Men need to inherit only one copy of the recessive allele for the condition to be fully expressed
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Women simply do not develop the disease regardless of their genetic composition
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The sex chromosomes are more active in men than in women
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Detailed explanation-1: -Because it is unlikely that females will have two altered copies of this gene, males are affected by X-linked recessive disorders much more frequently than females. A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons (no male-to-male transmission).
Detailed explanation-2: -X-linked recessive diseases most often occur in males. Males have only one X chromosome. A single recessive gene on that X chromosome will cause the disease. The Y chromosome is the other half of the XY gene pair in the male.
Detailed explanation-3: -Fathers cannot pass X-linked recessive conditions to their sons. When a son inherits a mutated gene on the X chromosome from his mother, the genetic condition is more likely to occur. X-linked recessive conditions most often occur in males.
Detailed explanation-4: -X-linked recessive inheritance refers to genetic conditions associated with mutations in genes on the X chromosome. A male carrying such a mutation will be affected, because he carries only one X chromosome. A female carrying a mutation in one gene, with a normal gene on the other X chromosome, is generally unaffected.
Detailed explanation-5: -Males can only get an X chromosome from their mother whilst females get an X chromosome from both parents. As a result, females tend to show higher prevalence of X-linked dominant disorders because they have more of a chance to inherit a faulty X chromosome.