When light energy excites electrons in photosystem ii, where do the electrons to replace them come from?

Amutagen is 1: a living thing that has undergone a mutation. 2: an agent that causes a mutation in dna. 3: a mutation that has affected one gene. 4: a chemical that can poison living cells.

What links the two strands in a dna helix together in the middle? a. phosphate groups b. sugar rings bonded together c. proteins d. bases with hydrogen bonds

What evidence did mendel find that supported his law of independent assortment? a. some traits are controlled by several different genes. b. a trait can be passed on from a parent to an offspring. c. most traits have a dominant form and a recessive form. d. different traits are passed on independently of each other.