Impressions of tropical swamp plants were observed on rocks in polar regions. the impressions were dark black imprints, which means the fossils are examples of . the fossils tell us that polar regions .

What does the hardy-weinberg principle relate to? a. chances of survival of an organism b. frequency of alleles in a population c. natural selection in a species d. causes of evolution among organisms

Which example describes a mutualistic relationship between organisms? young wasps prey on caterpillars. crabs eat the remains of dead fish. tapeworms feed on food in the intestines of cats ants protect a tree on which they feed.

Nitrogen-14 and nitrogen-15 are isotopes of the same element. how do these two isotopes differ? a. they have different numbers of nuclei. b. they have different numbers of protons. c. they have different numbers of neutrons. d. they have different numbers of electrons.