Distinguish between smooth endoplasmic reticulum and rough endoplasmic reticulum.(1 point) Smooth endoplasmic reticulum has ribosomes attached to its surface.

Smooth endoplasmic reticulum has vacuoles attached to its surface.

Rough endoplasmic reticulum has ribosomes attached to its surface.

Rough endoplasmic reticulum has vacuoles attached to its surface.

The gene that causes sickle-cell disease is present in a higher percentage of residents of sub-saharan africa than among those of african descent living in the united states. even though this gene causes sickle-cell disease, it also provides some protection from malaria, a serious disease that is widespread in sub-saharan africa but absent in the united states. discuss an evolutionary process that could account for the different percentages of the sickle-cell gene among residents of the two regions.

Which conditions are necessary for natural selection to occur? select all of the answers that apply. a. inheritable adaptations vary among individuals. b. the population size is increasing. c. more individuals are born than can survive. d. fitness varies among individuals. e. the environment changes suddenly and drastically.

Apuppy’s tendency to chew is inherited through which of the following? a. through learned behavior b.through genes c. through seasonal cycles d. through hibernation