It can fertilize from when you are a young age. Sometimes from the age of 11 and up
Fertile men should have sperm that is between light gray to off-white. There is not a perfect color that will indicate fertility.
NO
Sperm of a fertile male.
You can't.
How long sperm can survive in the female body depends on how healthy the sperm are and whether the female is fertile at the time. If there is fertile quality cervical mucus present then sperm can potential survive for up to a week within her body.
It doesn't depend on how much of sperm is produced for a man to be fertile but it depends on the quality of the sperm. Many lifestyle factors affect the quality of sperm, eg. Smoking, excessive alcohol intake , temperature at which the testicles are kept at, etc.
they gave females fertile sperm.
the sperm finds a fertile egg and makes a baby
Yes, however sperm count decreases with age.
The sperm must have an X chromosome as opposed to a Y chromosome.
In males, the testis become larger and can produce mature sperm. in males, the ovaries become fertile. Only fertile sperm and eggs can reproduce.
Average males usually become potentially fertile (produce sperm) at age 13, however aren't fully fertile until age 14-16. See link in related links.