What Can Be Inferred About a Genetic Disorder That, When

question 33

Multiple Choice

What can be inferred about a genetic disorder that, when it occurs in monozygotic twins, affects one twin 80% of the time and affects both twins only 20% of the time?

• A)Expression of homologous genes is influenced by the gender of the parent who contributed them.
• B)Nongenetic factors can influence the expression of identical alleles.
• C)The mutation occurred in a somatic cell rather than a germ cell.
• D)Mutation repair is incompletely penetrant.

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Definitions:

Food Chain

A series of organisms each dependent on the next as a source of food, illustrating the flow of energy and nutrients from one organism to another.

Ecological Pyramid

A graphical representation of the relative energy value at each trophic level. See pyramid of biomass and pyramid of energy.

Trophic Levels

The hierarchical levels in an ecosystem, determined by the feeding position of organisms in food chains.

Energy Loss

The reduction in energy as it moves through the trophic levels of an ecosystem; often described in the context of the inefficiency of energy transfer between levels.