<prompt> Maximum fraction of semen is contributed by:Seminal VesiclesProstateBulbourethral glandsAll contribute equally  <response>: Some important points regarding spermatogenesis:Sperms are produced in: seminiferous tubules in testes.Sertoli cells nurture the developing sperms.Time for spermatogenesis: 64 days Thymidine labelling records say it is 74 days.Normal sperm count: 20 million per ml or 40 million per ejaculate.Infertility is considered with a sperm count of less than 15 million spermsml.Fructose is the main source of energy for sperms.Prostaglandins suppress immune response against sperms in the female reproductive tract.Zinc serves to help to stabilize the DNA-containing chromatin in the sperm cells.Acrosomal cap houses the various enzymes needed to penetrate the zona pellucida of the oocyte. 