Which of the following is an atom that has gained an electron? select one: a. positive ion b. nonpolar molecule c. polar molecule d. negative ion

Place the steps tor the formation of the enzyme pepsinogen in correct order

How can antibodies "remember" a particular bacterial invader or "antigen" on that invader?

What evidence supports the law of conservation of energy? a) mechanical energy is converted to chemical energy during photosynthesis. b) oxygen is made from the breakdown of carbon dioxide during photosynthesis. c)energy is absorbed by chlorophyll and becomes chemical energy during photosynthesis. d)the sun gives off light energy that is absorbed by plants.