Sickle-cell anemia is a disease that is caused by a change in the gene sequence by one amino acid two amino acids three amino acids four amino acids

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

The smallest biological units that can evolve are

Select the correct answer. which of the following statements is a scientific claim? a. the early solar system had large amounts of water; so, the oldest objects in the solar system should also be abundant in water. b. the mass of the universe is much greater than current models predict; it is not possible to explain this inconsistency. c. planet earth is abundant in water, but there is no way to scientifically determine from where earth's water originated. d. earth is shaped like a sphere even if not all of the scientific observations related to its shape support this idea.