Which stain is used for electron microscopy?

Which of the following statements is/are correct?
$(i)$ The endomembrane system includes plasma membrane,$ER$,Golgi complex,lysosomes and vacuoles.
$(ii)$ $ER$ helps in the transport of substances,synthesis of proteins,lipoproteins and glycogen.
$(iii)$ Ribosomes are involved in protein synthesis.
$(iv)$ Mitochondria help in oxidative phosphorylation and generation of $ATP$.

The $GERL$ system was proposed by:

Arrange the following cell organelles in ascending order of their size:

Match the following.

$A$. Microfilament	$i$. Glycocalyx
$B$. Microtubule	$ii$. Actin
$C$. Flagella	$iii$. Tubulin
$D$. Outer layer of bacteria	$iv$. Outer compartment

Eukaryotic cells have organelles which may:
$(a)$ not be bound by a membrane
$(b)$ be bound by a single membrane
$(c)$ be bound by a double membrane
Group the various sub-cellular organelles into these three categories.