Which of the following cells secrete testicular hormones called androgens and form endocrine part of the testis?
Leydig cells
Interstitial cells
Sertoli cells
Both $(a) \;\&\; (b)$
During the development, the point of entry of sperm in the eggs at fertilization
$A$ : Development is the emergence of a multicellular organism from a single group of cells.
$R$ : Development involves growth, differentiation and morphogenesis.
In the development of the human body, the ectoderm is responsible for the formation of
The rolling of endodermal and mesodermal cells from the surface of embryo into its interior is called
The animals in which complete embryo develops in the mother's body through placenta are