Homologous structures have different mature forms in different organisms but develop from the same: a. vestigial organ
b. fossil
c. embryonic tissue
d. none of the above

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