Mitochondrial $DNA$ is - ..........

$ATP$ synthesis occurs on the

$A$: Mitochondria are the powerhouses of the cell.
$R$: The sites of the Krebs cycle and oxidative phosphorylation in cellular respiration are within the mitochondria.

$Assertion (S):$ $F_1$ particles contain the components necessary for oxidative phosphorylation.
$Reason (R):$ The mitochondrial matrix contains enzymes required for glycolysis.

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

Mitochondria is the site of