Fertilization occurs when sperm cells from a male's testes are deposited
near an egg cell from the female ovary, and one of the sperm cells enters
the egg cell. Most of the time, by chance or design, a sperm never arrives
or an egg isn't available.
| NSES Content Standard C
Life Science: Reproduction and heredity Grades 5-8, page 157 In many species, including humans, females produce eggs and males produce sperm. Plants also reproduce sexually--the egg and sperm are produced in the flowers of flowering plants. An egg and sperm unite to begin the development of a new individual. That new individual receives genetic information from its mother (via the egg) and its father (via the sperm). Sexually produced offspring never are identical to either of their parents. |