Genes work in?

Appeared in: AIIMS Nagpur NO - 2018

Explanation

Genes are the basic units of heredity and are located on chromosomes.
In diploid organisms like humans, chromosomes exist in homologous pairs, with one chromosome inherited from each parent.
Consequently, genes also exist in pairs. Each gene in a pair is called an allele.
This pair of alleles, one from each parent, works together to determine an individual's specific traits.

Option A: Traits are the observable outcomes or characteristics (e.g., eye color) that result from the expression of genes. Genes code for traits; they don't work 'in' them.
Option C: While some complex traits are influenced by groups of genes (polygenic inheritance), the fundamental unit of action for simple Mendelian traits is a pair of genes (alleles).
Option D: In diploid organisms, including humans, genes do not work singly. A single gene represents only half of the genetic information for a particular trait. Genes function singly in haploid organisms (like bacteria) or in gametes (sperm and egg cells).

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain The fundamental principle of how genes are organized and function in diploid organisms as background academic context rather than a clinical decision trigger.
Understanding that genes work in pairs is crucial for genetic counseling and predicting the risk of inherited diseases.
For recessive disorders (e.g., Cystic Fibrosis, Sickle Cell Anemia), an individual must inherit two copies of the faulty gene (one from each carrier parent) to be affected. Knowing this helps in screening and family planning.
For dominant disorders (e.g., Huntington's Disease), inheriting just one faulty gene from an affected parent is enough to cause the disease. This explains why it appears in every generation.

How to Approach the Question

Identify the core concept: The question asks about the fundamental functional arrangement of genes.
Recall basic biology: Humans are diploid organisms, meaning our cells contain two sets of chromosomes (23 pairs).
Connect chromosomes to genes: Genes are segments of DNA located on chromosomes.
Deduce the answer: Since chromosomes come in pairs (one from each parent), the genes on them must also function in pairs.
Evaluate the options: 'Pairs' directly reflects this biological principle. 'Traits' are the result, not the mechanism. 'Group' is too general, and 'single' is incorrect for diploid organisms.

Concept Tested & Keywords

Concept Tested: The fundamental principle of how genes are organized and function in diploid organisms.
Stem keywords: Genes, work in
Lead-in keywords: BEST, MOST RELEVANT CLUE
Negative lead-in flag: false

QD7C8Ri4VdQqnB_Mtyp-76

E6 Pathology-Vandana Puri & Kavita Gaur Textbook of Pathology and Genetics p. 485-487

Practise the full AIIMS Nagpur NO - 2018

Attempt every question from this paper in a timed mock, then review the full solution for each one.