Exercise and working out
Yes, as long as the testicle is functioning properly then you can reproduce with one testicle.
Yes, he has only one testicle.
yes you can (I did)
Sticking a needle through a testicle could cause severe pain, bleeding, infection, and damage to the delicate structures inside the testicle, including the blood vessels and the spermatic cord. It is a very dangerous and harmful act that could lead to serious complications and permanent damage.
If it doesn't hurt and you seem to be functioning properly, you are probably fine. It is not uncommon for an injury to cause one testicle to hang lower than the other permanently.
Can a man with one testicle breed? The answer is YES
Most often a bump on a testicle is a cyst, called a varicocoele, which is harmless. However it could be more serious and its important to have a doctor check it out.
I don't really see how it's physically possible for a man's testicle to just disappear, but if it's happened to you, I'd suggest seeing a doctor as soon as possible.
Many males have a testicle , which is larger then the other one.
Well, it depends there are two. Orchioplexy is the surgical procedure to move an undescended testicle into the scrotum and permanently fix it there. It is mainly done in children under the age of two, since the testicles are supposed to be permanently descended by the age of one. The other is orchiectomy, which is the surgical removal of the testicle. This must be done if the testicle has been in the abdomen too long since an undescended testicle can cause testicular cancer.
A guy with one testicle will have the same change in his voice that he would have if he had two.