Which one of the following is not included under the endomembrane system?

Consider the following statements and choose the incorrect option:
$a$. Large and more numerous nucleoli are present in cells actively carrying out protein synthesis.
$b$. Nuclear pores allow bidirectional movement of molecules.
$c$. Cytoskeleton is a glycolipid structure for mechanical support,motility and maintenance of the shape of the cell.
$d$. Steroidal hormones are synthesized by Golgi complex.

What do mature mammalian $RBCs$ lack?

In the following,which is not common for chloroplasts and mitochondria?

Match the following columns:-
List-$I$ List-$II$
$(a)$ Cristae $(i)$ Flat membrane-bound sacs in stroma
$(b)$ Cisternae $(ii)$ Infoldings in mitochondria
$(c)$ Thylakoids $(iii)$ Disc-shaped sacs in Golgi apparatus
$(d)$ Kinetochores $(iv)$ Disc-shaped structures in chromosomes

The invention of the electron microscope led to a major breakthrough in the study of cells. What could be the reason for this?