Answer:
A zygote is the union of the sperm cell and the egg cell . Also known as a fertilized ovum, the zygote begins as a single cell but divides rapidly in the days following fertilization. After this two-week period of cell division, the zygote eventually becomes an embryo.
Explanation:
They may have different phenotypes because of differences in their environments, such as nutrition and healthcare.
a star expels most of its outer material until only the hot core remains, which then settles down to become a young a white dwarf
Scar tissue is made of a protein called collagen
