The overall Count will be a bit lower, but if that testicle is healthy, the man will still be fertile.
Yes, as long as the testicle is functioning properly then you can reproduce with one testicle.
Not if only one testicle is removed. You can produce sperm just fine with only one testicle
One testicle can still produce millions of sperm. Your sperm output is more likely to be affected by other things (tight or too warm clothing, diet, alcohol, drugs etc).
Yes ... although the amount of sperm may not be sufficient to fully fertilize the ovaries.
If he has a testicle, there will be sperm.
Can a man with one testicle breed? The answer is YES
Nope, each testicle both produces and stores the sperm.
It should not affect performance however may effect sperm count and reproductive capability.
Absolutely - the man would simply be unable to sire children.
Err... Assuming you have 2 testicles... 100% Divided by 2 = 50% So 50% in each testicle :)
uni
Had, past tense. Either it came down on it's own or with help. Either way, you only need one to produce sperm and both may be working. There may be other issues, but by itself, one undecended testicle should not stop you from producing sperm.