Which cell structure is the gatekeeper, controlling what goes in and out of the cell? a) c - nucleus b) e - vacuole c) a - cell membrane d) b - endoplasmic reticulum

Waianapanapa beach in hawaii is a black-sand beach that was formed by waves crashing against volcanic rock. the sand can be very hot on sunny days. which statement best explains why? o a. the black sand has no heat capacity. b. the black sand absorbs no radiation. o c. the black sand is immune to insolation. d. the black sand has a low albedo.

Explain the source of radioactivity in uranium in earth’s crust by which it produces nuclear radiation

Which kind of worm has a closed circulatory system? a planarian b fluke c pinworm d an earthworm