Bald Eagle Populations Reached Such Low Numbers in the 1960s

question 20

Multiple Choice

Bald eagle populations reached such low numbers in the 1960s that some biologists predicted their extinction in the continental United States; what action appears to have been most significant in reversing their decline?

• A) Eagle sanctuaries were established to provide protection for nesting eagles.
• B) Bounties on eagle predators were enacted.
• C) The use of DDT was banned in the United States.
• D) Eagles were reared in captivity until reaching an age of self-sufficiency and then returned to the wild.

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Definitions:

Lipid-Soluble

Refers to molecules capable of dissolving in fats, oils, and non-polar solvents, which allows them to easily pass through cell membranes.

Autocrine

A mode of hormone action where a cell secretes a hormone or chemical messenger that binds to autocrine receptors on the same cell, leading to changes in the cell.

Conjugated

Compounds that are linked or coupled, especially in the context of organic chemistry or biochemistry, such as conjugated proteins.

Neurotransmitter

Chemical substances that transmit signals across a synapse from one neuron to another target neuron, muscle, or gland.