Final answer:
The absence of Sertoli cells in male sexual development results in infertility due to disrupted spermatogenesis, despite normal male external genitalia formation due to testosterone from Leydig cells.
Step-by-step explanation:
Without Sertoli cells, male sexual development would be significantly impaired. Sertoli cells play a critical role in the process of spermatogenesis as they create a blood-testis barrier, provide nourishment to developing sperm cells, and secrete inhibin which regulates testosterone levels and sperm production. Without them, even though Leydig cells produce testosterone leading to the formation of male external genitalia, the male would be infertile as spermatogenesis would not occur.
The SRY gene on the Y chromosome is responsible for coding testes development. In sexual development, Sertoli and Leydig cells play important roles. If only Sertoli cells were absent, the development of male sexual organs would be affected.
Sertoli cells are crucial for the maturation and nourishment of sperm cells. They provide support and produce proteins and enzymes necessary for sperm development. In the absence of Sertoli cells, sperm maturation and development would be impaired, leading to infertility.