Which of the following show phagocytosis?

Identify the correct sequence starting from the synthesis of protein to its transportation and packaging.

Which organelle has a single membrane?

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

Match List-$I$ with List-$II$.

List-$I$	List-$II$
$(a)$ Cristae	$(i)$ Primary constriction in chromosome
$(b)$ Thylakoids	$(ii)$ Disc-shaped sacs in Golgi apparatus
$(c)$ Centromere	$(iii)$ Infoldings in mitochondria
$(d)$ Cisternae	$(iv)$ Flattened membranous sacs in stroma of plastids

Choose the correct answer from the options given below.

Assertion $A$: Organelles in eukaryotic cells are membrane-bound.
Reason $R$: Organelles in prokaryotic cells are non-membrane-bound.
Which option is correct for Assertion $A$ and Reason $R$?