Which statement supports the theory of evolution by natural selection?
A. Organisms change when the survival rate of
offspring begins to decrease.
B. Mutations occur in species that are not suited
for their environment.
C. Evolution is the result of mass extinctions of
species in different ecosystems due to a lack
of genetic diversity
D. Characteristics of populations can change over
time in response to environmental changes.
8.

Choice D

Explanation: Natural selection explains how the strong survive due to mutations to suit the environment.

what statement best describes the difference between the sympathetic and parasympathetic nervous systems?

the sympathetic nervous system prepares the body for intense physical activity and is often referred to as the fight-or-flight response. the parasympathetic nervous system has almost the exact opposite effect and relaxes the body and inhibits or slows many high energy functions.

the solute can move "downhill," from regions of higher to lower concentration, relying on the specificity of the protein carrier to pass through the membrane. this process is called passive transport or facilitated diffusion, and does not require energy.