Dark Matter only: detected through its gravitational attraction, has mass, most common form of mass in the halo of the Milky Way Galaxy, likely to consist of subatomic particles
Dark Energy only: inferred to exist from the measured acceleration of the universe's expansion, the proposed source of a universal repulsive force
BOTH: the universe contains more of this than it contains matter made from atoms, we do not know what it is made of
NEITHER: blocks light from stars behind it, "dark" because it emits only infrared light
Answer:
Mutations, gene flow, and sexual reproduction are all major causes of variation. By altering the genes of individuals in a population, DNA mutation causes genetic variation. As new individuals with different gene combinations migrate into a population, they cause genetic variation.
Explanation:
B)
True, if it's absolutely frozen <span />
Something big; example: a pool
