Which of the following cannot pass through the placenta into the foetus

The breakage of the membrane surrounding the acrosome in a mammalian sperm is

The sperm produces substances of enzymatic nature called sperm lysin. In mammals, it is called

Which cavity arises by the invagination of endoderm and mesoderm

The correct sequence of spermatogenetic stages leading to the formation of sperms in a mature human testis is