Nucleus and Centrosome Structure — NEET Biology

Correct answer: A — A-iii, B-i, C-iv, D-v, E-ii, F-vi

The core concept tested is the comparison of cellular features and their distribution across prokaryotic and eukaryotic cell types, as detailed in NCERT. A. Organized nucleus with nuclear envelope: This is a defining characteristic of eukaryotic cells, distinguishing them from prokaryotic cells which lack such a nucleus. Thus, A matches with iii (Exclusive to eukaryotic cells). (NCERT Page 88). B. Ribosomes: These non-membrane bound organelles are found in all cells, both prokaryotic and eukaryotic, as they are essential for protein synthesis. Thus, B matches with i (Found in all living cells). (NCERT Page 88). C. Centrosome: This non-membrane bound organelle, which helps in cell division, is present in animal cells but typically absent in almost all plant cells. Thus, C matches with iv (Exclusive to animal eukaryotic cells). (NCERT Page 88, 91). D. Cell wall (plant type): Plant cells possess cell walls made of cellulose, hemicellulose, and pectins, which are generally absent in animal cells. Thus, D matches with v (Found in most plant eukaryotic cells). (NCERT Page 91, 94). E. Nucleoid region: In prokaryotic cells, the genetic material is naked and not enveloped by a nuclear membrane; this region is termed the nucleoid. Thus, E matches with ii (Characteristic of prokaryotic cells). (NCERT Page 90). F. Plasmid DNA: These are small circular DNA molecules found outside the genomic DNA in many bacteria (prokaryotes), conferring unique phenotypic characters. Thus, F matches with vi (Found in many bacteria). (NCERT Page 90). Therefore, the correct match is A-iii, B-i, C-iv, D-v, E-ii, F-vi. Final Answer: The final answer is A because the matching pairs are A-iii, B-i, C-iv, D-v, E-ii, F-vi.