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Question 584
Genetics → General
Classification
Question
SSBAOptions
Explanation
Deoxyribose and thymine identify the DNA-containing material, whereas ribose and uracil identify RNA. Most eukaryotic DNA is nuclear and packaged as chromatin, although some is present in organelles such as mitochondria. Prokaryotic DNA is mainly cytoplasmic. These distributions therefore fit preparations 1 and 2 respectively. Copying chromosome DNA before cell division is DNA replication, distinct from making an RNA transcript or synthesising a polypeptide.
Option Validity
A) This reverses the characteristic distributions: predominantly nuclear chromatin is eukaryotic, whereas predominantly cytoplasmic DNA is prokaryotic.
C) The cell distributions are correctly identified, but transcription creates an RNA copy from DNA rather than duplicating chromosome DNA.
D) Translation uses mRNA to direct polypeptide synthesis; it is not chromosome duplication.
E) Deoxyribose and thymine identify DNA. RNA contains ribose and uracil, and translation produces a polypeptide rather than copying either nucleic acid.
Further Reading
Saxena R. Textbook for MRCOG-1: Basic Sciences in Obstetrics and Gynaecology. Jaypee Brothers Medical Publishers; 2016. Chapter 8, Genetics: Deoxyribonucleic Acid and Process of Protein Synthesis. Printed pages 254–255.