What the contact between photosynthesis and respiration

Which of these is not a function of some membrane proteins ? a. allowing polar molecules to enter the cell b. recognizing other types of cells c. receiving messeges from other cells b. carrying messages to oher cells

Ablastocyst is a group of cells that forms after a human egg is fertilized. the blastocyst consists of two types of cells. some of these cells will become the placenta. what do the other cells develop into?

Which of these substances does not protect against invaders in the nonspecific immune response? a. saliva b. mucus c. tears d. urine