If my child has one undescended testicle, will he be able to produce the same amount of testosterone as a regular person?

Yes: Men with one testicle have normal sperm production and fertility. I am concerned about the undescended testicle, however. Undescended testicles should be surgically corrected, early in life to preserve the testicle's function; more importantly, to decrease the risk of testicular cancer. If the testes hasn't descended after 1 year of age, see a peds urologist or surgeon.

Yes: Children with one testicle as they grow up, they are able to have children without any problems, provided the other testicle is working well. The level of testesteron is less, but it doesn't affect the ability to have babies or secondary sexual characteristics.

Yes: Testosterone is produced by the leydig cells in the testes. Production is controlled by hormones (gonatropin-releasing hormone, luteinizing hormone & follicle-stimulating hormone) from the pituitary gland. If testosterone levels are low, increased secretion of these hormones will stimulate more production. Of note, the child should undergo orchidopexy for his undescended testicle.

Yes: There is no indication to the contrary.