Meiosis can be observed in
Primary spermatocytes
Secondary spermatocytes
Both $A$ and $B$
Mature sperm
The capsule enclosing testis of mammal is called as
Hormone responsible for metamorphosis in tadpole is
Find out $A, B$ and $C$ in the figure given below
Blood flowing in umbilical cord is
The amnion and chorion consist of which type of composition