Structure connecting the foetus to placenta is

Identify the correct option ($A$), ($B$), ($C$), ($D$) with respect to spermatogenesis.

The main function of tropho ectoderm in mammalian embryo is

Which one of the following statement is correct

Normally the gametes are disease free in human beings or even in other animals because

Vasa deferentia together with seminal vesicle forms