Why is the mitochondrion called the 'powerhouse of the cell'?

Why do plant cells possess large-sized vacuoles?

In a non-dividing cell,$DNA$ is present as part of chromatin material which can be seen as

Identify the type of cell and write one characteristic feature for each of the following descriptions:
$(i)$ Large vacuole,nucleus pushed to the periphery.
$(ii)$ Cell does not burst even in a very dilute medium.
$(iii)$ Nuclear region is not well-defined and is known as the nucleoid.

The undefined nuclear region of prokaryotes is also known as:

Name the plastid which stores starch,oils and protein granules.