Respiratory enzymes are present in the following organelle:

Organelles which are regarded as the “Powerhouse of the cell” and in which the oxidative reactions of the respiratory process take place are:

Read the statements $P$ and $Q$:
$P$: The number of mitochondria in each cell does not depend on the physiological activity of the cell.
$Q$: Mitochondria are present in both plant and animal cells.
Select the correct option from the given choices.

In the given figure,what does $B$ represent?

The mitochondrial $DNA$ differs from the nuclear $DNA$ because of:

Which was the first plant cell in which mitochondria were observed?