Question

Chromosomal aberration in which there is no loss or gain of gene complement is

• A. deletion
• B. duplication
• C. inversion
• D. translocation

Hint:

Think of inversion as reading a sentence backwards.
The words (genes) are all still there, just in reverse order, so the total amount of genetic information remains exactly the same.

Answer 1

The Correct Option is C

Step 1: Understanding the Problem:
Chromosomal aberrations involve changes to the macroscopic structure of a chromosome.
These structural changes can alter the number or the arrangement of genes on the affected chromosome.
Step 2: Approach and Formula:
Evaluate each type of structural mutation listed in the options based on whether genetic material is lost, gained, or merely rearranged.
Step 3: Detailed Explanation:
In deletion, a chromosomal segment is lost, causing a direct loss of gene complement.
In duplication, a chromosomal segment is repeated, causing an abnormal gain of gene complement.
In translocation, a segment is transferred to a non-homologous chromosome, changing the gene complement of individual chromosomes.
In inversion, a chromosomal segment breaks off, flips \(180^{\circ}\), and reattaches exactly in its original location.
Because the segment is only flipped and nothing is removed or added, there is no overall loss or gain of gene complement.
Step 4: Final Answer:
Inversion is the chromosomal aberration with no loss or gain of genes.