The villi which are formed by the allantochorion to form the intimate connection with uterine endometrium functions as
Gaseous exchange organ only
Attachment arrangement only
Placental structure
None of the above
$A$ : If both the ovaries are removed after the first trimester of pregnancy, still there would be normal growth of foetus.
$R$ : After first trimester placenta secretes sufficient progesterone
Capacitation occurs in
In frog chromosome no. is reduced to half
Function of fertilizin is/are
Given below is a diagrammatic sketch of a portion of human male reproductive system. Select the correct set of the names of the parts labelled $A, B, C, D.$