The process that moves materials through a membrane against a concentration difference known

What is a dendrite and what does it do?

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

According to cell theory; which structures carry out the basic function of living things? a. atoms b. organs c. cells b. nuclei