When sugar is used as a raw material, the end products obtained from fermentation are ......... .

Identify the products marked by $(i)$ and $(ii)$ in the following pathway:
$3$-phosphoglyceric acid $\rightarrow$ $(i)$ $\rightarrow$ Pyruvate $\rightarrow$ $(ii)$ (with $NADH + H^+$ being converted to $NAD^+$)

Fermentation is:

In anaerobic respiration,bacteria produce:

Respiration requires $O_2$. How did the first cells on the earth manage to survive in an atmosphere that lacked $O_2$?

Which molecule listed below is a product of fermentation of glucose by yeast?