Question: 128. A specialized membranous structure in a prokaryotic cell which helps in cell wall formation, DNA replication and respiration is:
(1) Mesosome
(2) Chromatophores
(3) Cristae
(4) Endoplasmic Reticulum
Answer: Option (1)
Explanation:
Mesosomes are specialized membranous structures formed by infoldings of the plasma membrane in prokaryotic cells.
They increase the surface area of the plasma membrane and are associated with important cellular functions.
Mesosomes help in cell wall formation, DNA replication, distribution of chromosomes to daughter cells, and respiration.
Chromatophores are photosynthetic membrane systems present in some photosynthetic bacteria.
Cristae are folds of the inner mitochondrial membrane found only in eukaryotic cells.
Endoplasmic reticulum is a membrane-bound organelle present only in eukaryotic cells.
Hence, the correct answer is mesosome.