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

Of the total enzymes present in the cell,approximately how many occur in the mitochondrion (in $\%$)?

The figure below shows the structure of a mitochondrion with its four parts labelled $(A), (B), (C)$ and $(D).$ Select the part correctly matched with its function.

The mitochondrion is the site of .........

Which process occurs in the part labeled 'a' in the given figure?

Which organelle has an electron transport system?