What are the infoldings of the cell membrane in bacteria called?

Which of the following is $NOT$ correct for prokaryotic organisms?

The nucleic acid polymer in the chromosome of bacteria is $..........$.

In the given figure,the structural components of $X$ and $Y$ are respectively ......... and ........ .

Which of the following statements about a bacterial cell is/are correct?
$(i)$ Mesosome is formed by the extensions of plasma membrane into the cell.
$(ii)$ The pili are elongated tubular structures made up of a protein.
$(iii)$ Flagellum is composed of filament,hook,and basal body.
$(iv)$ Ribosomes are about $30 \; nm$ by $50 \; nm$ in size.

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