The mantle of the moon Select one: a. is composed of two layers. b. may have high levels of iron. c. contains the mineral olivine. d. all of the these.

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

Which of the following occurs most often in a population when genetic variation and overproduction are present? some organisms have a lower reproductive success than others. some organisms have a higher reproductive success than others. some organisms have no reproductive success. some organisms do not have genetic variation.

What occurs to the cell during mitosis