Sertoli cells are regulated by the pituitary hormone known as:

In $\triangle ABC$,the midpoints of the sides $AB, BC$,and $CA$ are respectively $(l, 0, 0), (0, m, 0)$,and $(0, 0, n)$. Then,$\frac{AB^2+BC^2+CA^2}{l^2+m^2+n^2}$ is equal to

What is the small,circular $DNA$ molecule present in a bacterial cell,in addition to the main genomic $DNA$,called?

If ${}^n C_{r-1}=330$,${}^n C_r=462$,and ${}^n C_{r+1}=462$,then $r$ is equal to

In the standing wave shown,particles at the positions $A$ and $B$ have a phase difference of

$A$ conducting wire frame is placed in a magnetic field which is directed into the paper. The magnetic field is increasing at a constant rate. The directions of induced current in wires $AB$ and $CD$ are