Match Column $I$ with Column $II$ and choose the correct option.

Column $I$	Column $II$
$A$. Centrioles	$I$. Non-membrane bound organelle which helps in cell division
$B$. Fimbriae	$II$. Special structure of bacteria which help them to attach to rocks in streams
$C$. Endomembrane system	$III$. Includes those organelles whose functions are coordinated
$D$. Mitochondria	$IV$. Divide by fission and site of aerobic respiration

Which of the following show phagocytosis?

$A$ chemical substance that,when irradiated with $UV$ rays,absorbs radiation and emits visible light is called:

In the given figure,what do the labeled parts '$a$' and '$b$' represent respectively?

Identify the correct statements w.r.t. the given cell diagram:
$A$. Concerned with lipid and steroidal hormone synthesis.
$B$. Outer non-living rigid structure which gives shape to the cell and protects from mechanical damage and infection.
$C$. Both lie perpendicular to each other and each has an organisation like the cart wheel.
$D$. Responsible for trapping light energy for the synthesis of sugar.
$E$. Present in cells actively involved in protein synthesis and secretion.
$F$. Spherical structures,rich in hydrolytic enzymes.

The best microscope to study the fine structure of a cell is .....