Question

Examine the results from a nucleotide BLAST of a gene sequence $lcl2159$, identified in yellow.
Identify the most closely related species to the organism from which the DNA sample was isolated.

• A. Crocodile species are most closely related, as the gene has a more recent common ancestor.
• B. Alligator mississippiensis, since the mitochondrial DNA is similar to the gene.
• C. Crocodile species, since the distance tree of results shows the least distance between the gene sequence and these species.
• D. Caiman crocodilus, since the internal branch of the cladogram is connected to this gene sequence.

Answer 1

The correct option is A Crocodile species are most closely related, as the gene has a more recent common ancestor.

Answer is option A i.e. "Crocodile species are most closely related, as the gene has a more recent common ancestor"
BLAST (Basic Local Alignment Search Tool) finds regions of similarity between biological sequences.

BLAST program helps in phylogenetic tree construction by comparing nucleotide sequences to sequence database and finally calculating the statistical significance.

Phylogenetic tree represents evolutionary relationships among organisms. Two species are more related if they have a more recent common ancestor.