Question

Select the correct option:
Mesosomes are the infoldings of cell membrane, which
i) are present in both prokaryotic and eukaryotic cells.
ii) Help in cell wall formation, DNA replication and respiration.
iii) Increase the surface area of the plasma membrane.
A. i) and ii)
B. ii) and iii)
C. i) and iii)
D. i), ii) and iii)

Answer 1

Mesosomes are intracytoplasmic membranous structures. They are vesicular, convoluted or multi-laminated structures formed as invaginations of plasma membranes into the cytoplasm.

Complete answer:
Mesosome is a convoluted membranous structure formed by the infoldings of the plasma membrane in the form of vesicles, tubules or lamellar whorls. All prokaryotic cells have mesosomes. Prokaryotic cells have different types of nuclear envelopes and nucleolus is not present. It contains only one chromosome having a naked DNA, without protein. In prokaryotes, there are specific structures known as Mesosomes. They are the invagination of the plasma membrane. They are of vesicles, tubules and lamellae. The folded invagination increases the surface area of the plasma membrane. They help in the cell wall formation. They produce different enzymes like dehydrogenase and distinct components of the electron transport chain.
They help in DNA replication and respiration. The important feature is to enhance the surface area of the plasma membrane. There is an increase in surface area of the membrane helpful in cellular respiration. Mesosome helps in cell division, aiding cell wall synthesis, and DNA synthesis. Mesosomes help in the formation of crosswalk and enhance the bacterial DNA to the cell membrane. It helps in separation of bacterial DNA to daughter cells.

Hence, the correct answer is option (B).

Note: Mesosomes are membranous invaginations of plasma membranes. They help in the making of cell walls, DNA replication and distribution to daughter nuclei. They also assist in secretion and respiration.