Which organelle can be compared to a security guard who decides whom may enter a building and whom may not?
O cell membrane
O cytoplasm
O endoplasmic reticulum
O mitochondrion

Quick asap will give brainiest ! what best describes the same pattern of tides on earth throughout the day? neap tides spring tides semidiurnal tides nocturnal tides

About how much of the cell mass is watet

Which line in the graph above best illustrates an effect of the carbon dioxide level in the blood on breathing rate before, during and after a period of exercise? 1.b,2.c,3.a,4.d