From within the Moon's penumbra, a partial solar eclipse can be seen. Like any other opaque objects illuminated by a light source, the Moon and the Earth cast shadows into space as they block the sunlight that hits them. Each shadow has 3 different areas: the umbra, the penumbra, and the antumbra.
Answer:
B.secrete hormones directly into the bloodstream
Four egg cells are produced in meiosis but only one will actually be used.
Answer:
Natural selection
Explanation:
According to Darwin's theory, natural selection is the process by which individuals better adapted to their environments have more chances to survive and reproduce, and thereby their descendants will be better represented in the next generation. This mechanism exploits the existence of natural variation among members in the population which is used to select those individuals that are better adapted (i.e., with a higher adaptive fitness) for their environments. Natural selection is a key mechanism of evolution by which species change across time.
