What occurs in photosystem 2? a. water is split into hydrogen and oxygen b. carbon dioxide is made into sugar c. NADP and ADP are burned for energy d. The dark reaction PLEASE HELP!

Which of the following statements about archaea and bacteria is true? a. neither is single-celled. b. they both have nuclear membranes. c. neither reproduces by binary fission. d. they both lack a nuclear membrane.

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

Hemoglobin is a proton that carries oxygen around the body what is hemoglobin made from