There are many causes for a sperm being defective. Some of the leading causes are:
In a normal human male, up to 10% of Sperm cells are defective.
Lysosomes are the organelles that become defective in these diseases.
Impotence can be caused by many factors. Low sperm count, low testosterone, or defective sperm can be a cause. The best person to offer advice is one's physician.
No. No person on Earth can become pregnant without sperm.
You can become an sperm donor for contacting the sperm banks nearest to you; banks require that you are within 1 hour conmute from them.
When the ovum and sperm come together they become a fertlized egg also known as a zygote.
Only if it's gay sperm. If you eat gay sperm you'll become a lesbian.
Sure. Bearings and seals can wear out.
the other systems are not affected
If a man practice handjob regularly during his teenage, then his sperm count is reduced to such an extent that he may become sterile.
Technically one sperm cell can get you pregnant, but it is unlikely with one.
Sperm cells become potent around the age of seventeen and eighteen.