Question

Match List-I with List-II 

Choose the correct answer from the options given below: 
 

• (A) - (I), (B) - (II), (C) - (III), (D) - (IV)
• (A) - (II), (B) - (IV), (C) - (I), (D) - (III)
• (A) - (II), (B) - (I), (C) - (IV), (D) - (III)
• (A) - (IV), (B) - (II), (C) - (I), (D) - (III)

Hint:

To remember BLAST types: \textbf{blastn}: nucleotide vs nucleotide \textbf{blastp}: protein vs protein \textbf{blastx}: translated nucleotide query vs protein database \textbf{tblastn}: protein query vs translated nucleotide database \textbf{tblastx}: translated nucleotide query vs translated nucleotide database The 'x' always means the query is a nucleotide that gets translated. The 't' means the database is a nucleotide database that gets translated.

Answer 1

The Correct Option is C

Step 1: Concept Overview:
BLAST (Basic Local Alignment Search Tool) is a suite of programs designed to identify similar regions within biological sequences. Each program is tailored for specific comparison types (e.g., nucleotide-to-nucleotide, nucleotide-to-protein).

Step 2: Program Specifics:
Key BLAST programs and their functions:

(A) BLASTN: Compares a nucleotide query sequence against a nucleotide database. Matches description (II).

(B) BLASTP: Compares a protein query sequence against a protein database. Matches description (I).

(D) BLASTX: Translates a nucleotide query sequence into all six possible protein reading frames and then compares these translated sequences against a protein database. Description (III) accurately reflects this process: "Uses nucleotide sequences as queries and translates them in all six reading frames to produce translated protein sequences, which are used to query a protein sequence database." Matches description (III).

(C) TBLASTX: Translates both a nucleotide query sequence (in all six frames) and a nucleotide database (dynamically in all six frames) for a translated-vs-translated comparison. This is the most computationally intensive variant. Description (IV) is a precise match: "Uses nucleotide sequences, which are translated in all six frames, to search against a nucleotide sequence database that has all the sequences translated in six frames." Matches description (IV).

Step 3: Conclusion:
The correct pairings are: (A) with (II), (B) with (I), (C) with (IV), and (D) with (III). This corresponds to option (3).