In prokaryotes,which layer is the second layer of the cell envelope?

In bacteria,the mesosome is a specialized structure formed by the invagination of which component?

Assertion $A$: Prokaryotic organisms do not undergo development and differentiation into multicellular forms.
Reason $R$: Prokaryotic organisms are unicellular.
Which option is correct for Assertion $A$ and Reason $R$?

Read the sentences properly and select the correct option for mesosome.
$(i)$ Mesosome is an extension of the plasma membrane.
$(ii)$ These extensions are only in the form of spheres.
$(iii)$ Mesosomes help in cell wall formation and $DNA$ replication (not $RNA$ synthesis).
$(iv)$ They help in respiration.

Nucleoid is present in:

Which of the following components provides a sticky character to the bacterial cell?