Pollen grains of a plant,whose $2n = 28$,are cultured to get callus by tissue culture method. What would be the number of chromosomes in the cells of the callus?

$A$ lead bullet of mass $10 \ g$ travelling at $300 \ m/s$ strikes against a block of wood and comes to rest. Assuming $50\%$ of heat is absorbed by the bullet,the increase in its temperature is (Specific heat of lead $= 150 \ J/kg \cdot ^{\circ}C$) (in $^{\circ}C$)

On what basis are the three types of lichens classified?

The dental formula of a rabbit is .......

The relation between $(A)$ and $(B)$ is:

Which hormone produces an anabolic effect on protein and carbohydrate metabolism?