The structure that stores genetic information is the?

DSSSB - 29 August 2019 (Shift-1)

Pathology & Genetics

Easy

Appeared in: DSSSB - 29 August 2019 (Shift-1)

Explanation

Deoxyribonucleic acid (DNA) is the nucleic acid that carries the genetic information for the development, functioning, growth, and reproduction of all known organisms and many viruses.
DNA is a double-stranded molecule organized into a double helix structure, which provides stability for long-term information storage.
It contains the complete blueprint of all hereditary characteristics, with each gene being a part of a DNA molecule.
The information in DNA is encoded in the sequence of four nucleotide bases: Adenine (A), Guanine (G), Cytosine (C), and Thymine (T).

Option A: tRNA (transfer RNA) does not store genetic information. Its primary role is to act as a physical link between the mRNA and the amino acid sequence of proteins, transferring amino acids to the ribosome during protein synthesis.
Option B: RNA (Ribonucleic Acid) is a general term. While some viruses use RNA as their genetic material, in human cells, RNA's primary functions are related to the expression and transport of genetic information (e.g., mRNA, tRNA, rRNA), not its long-term storage.
Option D: mRNA (messenger RNA) is a temporary transcript of a gene's DNA sequence. It carries the genetic 'message' from the DNA in the nucleus to the ribosomes in the cytoplasm for protein synthesis. It is a messenger, not a permanent storage molecule.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Storage of Genetic Information as background academic context rather than a clinical decision trigger.
Understanding the role of DNA is fundamental to nursing practice, as it is the basis of many genetic diseases (e.g., cystic fibrosis, sickle cell anemia, Huntington's disease).
Nurses educate patients about genetic testing, counseling, and the implications of hereditary conditions for their health and family.
Pharmacogenomics, a growing field, uses a patient's genetic information (from DNA) to guide drug therapy, helping nurses understand why certain patients respond differently to medications.

How to Approach the Question

First, identify the key action word in the question stem: 'stores'. The question is asking about the molecule responsible for the long-term storage of genetic information.
Next, recall the primary functions of the major nucleic acids. DNA is known as the 'blueprint of life' and is responsible for storing genetic data.
Evaluate each option: RNA and its subtypes (mRNA, tRNA) are primarily involved in 'expressing' or 'transferring' the information stored in DNA to create proteins.
mRNA is a temporary 'message', and tRNA is a 'transfer' molecule. Neither is for permanent storage.
Therefore, by eliminating the options related to the transfer and expression of genetic information, DNA remains as the correct choice for storing it.

Concept Tested & Keywords

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