Anaerobic respiration was first demonstrated by whom?

Select the statement which is not related to fermentation.

Which of the following organisms is widely accepted to respire in the absence of oxygen?

Acidic $pH$ of muscles is due to -

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 $NAD^+$)

The number of glucose molecules required to produce $38$ $ATP$ molecules under anaerobic conditions by a yeast cell is