Which scientist first discovered antibiotics?

What did Fa-Hien and Wanse discuss?

The correct sequence of stages of the growth curve for bacteria is:

Medicines are either man-made (i.e.,synthetic) or obtained from living organisms like plants,bacteria,animals,etc.,and hence,the latter are called natural products. Sometimes,natural products are chemically altered by man to reduce toxicity or side effects. Write against each of the following whether they were initially obtained as a natural product or as a synthetic chemical: $(a)$ Penicillin $(b)$ Sulphonamide $(c)$ Vitamin-$C$ $(d)$ Growth hormone.

$A$ large number of organic compounds can be decomposed by

From the given below,which one increases vitamin $B_{12}$ in our stomach and also plays a very beneficial role in checking disease-causing microbes?