Q.21 Synteny refers to
(A) gene duplication from a common ancestor
(B) a tree representation of related sequences
(C) the extent of similarity between two sequences
(D) local conservation of gene order

Synteny describes the conserved arrangement of genes on chromosomes across species. The correct answer to the multiple-choice question is option (D).

Correct Answer

D) local conservation of gene order.​
This concept highlights how blocks of genes maintain their relative positions and sequence from a common ancestor, aiding evolutionary studies and genome mapping.​

Option Breakdown

A) Gene Duplication from a Common Ancestor

Gene duplication involves creating extra gene copies through mechanisms like tandem or whole-genome events, leading to paralogs.
This differs from synteny, which focuses on positional conservation rather than copy number increase.​

B) A Tree Representation of Related Sequences

Phylogenetic trees visualize evolutionary relationships among sequences based on similarity or divergence.
Synteny instead examines physical gene layout on chromosomes, not branching diagrams.​

C) The Extent of Similarity Between Two Sequences

Sequence similarity measures nucleotide or amino acid identity, often via alignment tools like BLAST.
Synteny goes beyond pairwise similarity to emphasize chromosomal order preservation across genomes.​

Why Synteny Matters

Researchers use synteny to infer evolutionary history, identify orthologs, and assemble genomes by comparing conserved blocks.​
In biotechnology, it supports gene function prediction and comparative genomics for applications like microbial engineering.​