Name the functional unit of $DNA$ that carries genetic information.

What is the role of smooth endoplasmic reticulum in the liver cells of vertebrate animals?

Which cell organelle plays a crucial role in detoxifying many poisons and drugs in a cell?

Find out the false sentences from the following:
$I$. Golgi apparatus is involved with the formation of lysosomes.
$II$. Nucleus,mitochondria and plastid have $DNA$; hence they are able to make their own structural proteins.
$III$. Mitochondria is said to be the power house of the cell as $ATP$ is generated in them.
$IV$. Cytoplasm is called as protoplasm.

State the reason for the following:
$(i)$ Mitochondria are known as the powerhouse of the cell.
$(ii)$ Plastids are able to make their own protein.
$(iii)$ Plant cells shrink when kept in a hypertonic solution.

What is the significance of
$(a)$ presence of cell sap in vacuoles?
$(b)$ presence of $SER$ in liver cells?
$(c)$ presence of ribosomes on $RER$?