A male patient presents with infertility and upon examination, it's found that he has immotile sperms lacking a functional flagellum. Genetic analysis reveals a mutation affecting a specific protein crucial for flagellar structure. Which of the following proteins is MOST likely affected?

A researcher is studying the hormonal control of spermatogenesis. He administers a drug that selectively blocks the receptors for a specific hormone in the testes. As a result, he observes a significant decrease in the rate of spermatogenesis, but testosterone levels remain normal. Which hormone's receptors are MOST likely being blocked by the drug?

A male patient presents with infertility and upon examination, it's found that he has immotile sperms lacking a functional flagellum. Genetic analysis reveals a mutation affecting a specific protein crucial for flagellar structure. Which of the following proteins is MOST likely affected?

A rare genetic disorder affects the Sertoli cells within the seminiferous tubules, specifically impairing their ability to produce Androgen Binding Protein (ABP). Which of the following would be the MOST likely direct consequence of this disorder?