Single Change in the Last Several Decades Has Had the Largest

question 29

Multiple Choice

single change in the last several decades has had the largest positive effect on the average income of current elderly persons in the United States?

• A) More women have worked, and so earn retirement income.
• B) Men are living longer, so there are more couples earning the higher male retirement incomes.
• C) Individual Retirement Accounts (IRAs) were created.
• D) Social Security benefits have significantly increased.

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Definitions:

Germline Mutation

A germline mutation is a mutation that affects the gametes (eggs, sperm) of an individual and can be transmitted from parents to offspring. Germline mutations create the heritable genetic variation that is relevant to evolution.

Frameshift Mutation

A genetic mutation caused by insertions or deletions of a number of nucleotides that is not divisible by three, leading to a shift in the reading frame of codons and potentially altering protein function.

Phenotypic Plasticity

The potential of an organism to transform its observable traits in adaptation to environmental variations.

Genetic Polymorphisms

The occurrence of two or more distinct forms of a gene within a population, contributing to genetic diversity.