Natural selection tends to increase what ?

The frequency of genes within a population for traits that promote greater reproductive success.

Explanation:

Natural selection can either shift the mean value of a trait, reduce the trait's variation, or increase its variation.

a researcher conducts an experiment on the secretion of a particular hormone in mice. scientists inject mice with a substance that stimulates the production of the hormone. the scientists then test the levels of hormones produced by the mice. the tool used to measure the hormones consistently detects the levels at 10 points lower than the actual hormone levels in the mice. this tool makes measurements, but the measurements aren't .

explanation:

no u

answer; both surfaces of the membrane are nonpermeable