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

Which of the following pairs are correctly matched?
$(I)$ Amyloplasts - Store proteins
$(II)$ Mitochondrion - 'Power house' of the cell
$(III)$ Stroma - Chlorophyll pigment
$(IV)$ Axoneme $- 9+2$ array

Select the correct option for the following matches:

Column-$I$	Column-$II$
$(1)$ Mesosome	$(a)$ Not a component of the endomembrane system
$(2)$ Peroxisome	$(b)$ Many ribosomes associated with a single $m-RNA$
$(3)$ Polysome	$(c)$ Single membrane-bound system
$(4)$ Lysosome	$(d)$ Infoldings of the cell membrane

Which of the following cellular organelles are membrane-bound?

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

Read the following statements and identify the correct option:
$(A)$ Prokaryotic cells lack a nuclear membrane,chloroplasts,mitochondria,microtubules,and pili.
$(B)$ Eukaryotic cells contain a nuclear membrane,chloroplasts,mitochondria,microtubules,and pili.
$(C)$ Many bacterial cells have small circular $DNA$ outside the genomic $DNA$.