Sertoli cells are regulated by the pituitary hormone known as:

Chloramphenicol and erythromycin (broad spectrum antibiotics) are produced by

The sum of the coefficients in the expansion of $(1+x+x^2)^n$ is

$A$ $20 \, cm$ length of a certain solution causes right-handed rotation of $38^\circ$. $A$ $30 \, cm$ length of another solution causes left-handed rotation of $24^\circ$. The optical rotation caused by a $30 \, cm$ length of a mixture of the above solutions in the volume ratio $1 : 2$ is:

Which type of chromosome is shown in the figure below?

The image of the point $(3, 2, 1)$ in the plane $2x - y + 3z = 7$ is