Answer:
Four conditions are needed for natural selection to occur: reproduction, heredity, variation in fitness or organisms, variation in individual characters among members of the population.
Answer:
Pb has an atomic mass of 82. If an atom of that element has an atomic mass of 80, that atom is known as: an isotope.
Answer: Alveoli
Explanation: Alveoli of lungs are surrounded by extensive blood capillaries. The partial pressure of oxygen in the alveoli is higher than the blood entering the pulmonary capillaries, hence oxygen moves into the blood. Carbon dioxide in the lungs simultaneously diffuse out of the blood into the alveolar space.
Answer:
This submarine Mid-Atlantic Ridge owes its formation to the movement of the continental plates on either side of the ocean. As these plates slowly separate, they leave gaps in the earth's crust. This allows molten rock from beneath the earth's crust to reach the surface, forming a new part of the ocean floor
