The cell membrane is selectively permeable. Which type of membrane protein best illustrates this concept? A. channel
B. marker
C. receptor
D. hormone

Which statement describes john tuzo wilson’s contribution to the theory of plate tectonics?

How many chromosomes does each human cell contain? a. 23 chromosomes b. 26 chromosomes c. 43 chromosomes d. 46 chromosomes

Producing disposable grocery bags consumes resources. recycling disposable bags is a solution that can recover some of the resources used to make new bags. which of the following behaviors could further refine the solution? a. disposing of bags by burning them b. reusing bags whenever possible c. using bags at once so that they do not break d. using only nonrenewable materials to make new bags subject is environmental science for apex users