Place the rock layers in order from oldest to youngest in the blanks below. Type the letters as they are shown.

Amouse that is homozygous for the dominant trait has the genotype . it has . a mouse that is homozygous for the recessive trait has the genotype . it has . image of fur color of mice

What do isotopes of uranium have the same number of? what do they have a different number of? a) same number of protons; different number of electrons b) same number of protons; different number of neutrons c) same number of electrons; different number of protons d) same number of neutrons; different number of protons

Which of the following was not a major animal on land during the carboniferous period? amphibians insects both a and b none of the above