D the sun because it is the main leading producer for all living organisms
Muscle cells are also called fibers because they are like tissues and move easily
Since the trait is dominant, it is possible for his parents to be heterozygous (Bb). So they have the trait but they have a gene they can pass on with out it. If both of his parents Bb then he could’ve gotten both recessive and therefore not receive the trait
The Milky Way is a spiral galaxy
hope this helps:)