Mesosomes: Structure & Functions — NEET Biology

Correct answer: A — A-iii-q, B-ii-p, C-i-s, D-iv-r, E-v-t

NCERT core concept: The relationships between cellular components, their specific locations, and their primary functions. A. Fluid mosaic model: Correctly matched with 'iii. Plasma membrane (eukaryotic)' and 'q. Explanation of membrane fluidity and functions like endocytosis.' This model (Singer and Nicolson, 1972) describes the quasi-fluid nature of the eukaryotic plasma membrane, important for functions like endocytosis (NCERT page 94). B. Ribosomes: Correctly matched with 'ii. Cytoplasm (free or attached to ER/Mitochondria/Chloroplast)' and 'p. Site of protein synthesis.' Ribosomes are non-membrane bound organelles found in the cytoplasm, on ER, and within chloroplasts and mitochondria, serving as the site of protein synthesis (NCERT page 88-89, 98). C. Mesosome: Correctly matched with 'i. Prokaryotic cell plasma membrane' and 's. Involved in cell wall formation, DNA replication, respiration.' Mesosomes are specialized membranous structures formed by infoldings of the prokaryotic plasma membrane, assisting in cell wall formation, DNA replication, and respiration (NCERT page 91). D. Tonoplast: Correctly matched with 'iv. Vacuole' and 'r. Facilitates transport of ions against concentration gradient into vacuole.' The tonoplast is the single membrane bounding the vacuole, which facilitates the transport of ions and other materials against concentration gradients into the vacuole (NCERT page 96). E. Pericentriolar materials: Correctly matched with 'v. Centrosome' and 't. Amorphous materials surrounding centrioles.' The centrosome is an organelle containing two centrioles, which are surrounded by amorphous pericentriolar materials (NCERT page 99). Recap: Cells are composed of various specialized components, each with a distinct structure, location, and functional role crucial for the cell's overall activity and survival.