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 Concept:
Chromosomal aberrations refer to structural changes in chromosomes that can affect the gene complement (the total number of genes).
These structural modifications are generally classified into deletion, duplication, inversion, and translocation.

Step 2: Key Formula or Approach:
Evaluate each type of chromosomal aberration to determine whether genetic material is lost, gained, or merely rearranged internally.

Step 3: Detailed Explanation:
Deletion refers to the loss of a chromosomal segment, which inevitably results in a loss of genes.
Duplication involves the presence of an extra chromosomal segment, leading to an abnormal gain of genes.
Translocation is the transfer of a chromosomal segment to a non-homologous chromosome, changing the gene complement of individual chromosomes.
Inversion occurs when a segment of a chromosome breaks off, rotates 180 degrees, and reattaches in the same location. Because the genetic material is only rearranged internally, there is no overall loss or gain of the gene complement.

Step 4: Final Answer:
The aberration with no loss or gain of genetic material is inversion, making option (C) correct.