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: Understanding the Concept:
BLAST (Basic Local Alignment Search Tool) is a family of programs used to find regions of similarity between biological sequences. Each program is specialized for a different type of comparison (nucleotide vs. protein).
Step 2: Detailed Explanation:
Let's break down the main BLAST programs:
(A) BLASTN: The 'n' stands for nucleotide. It compares a nucleotide query against a nucleotide sequence database. So, (A) matches with (II).
(B) BLASTP: The 'p' stands for protein. It compares a protein query against a protein sequence database. So, (B) matches with (I).
(D) BLASTX: The 'x' signifies translation. It takes a nucleotide query, translates it in all six possible reading frames, and compares the resulting six protein sequences against a protein sequence database. The description for BLASTX is not fully provided in the options, but part (III) is the best match. Let's read (III) carefully: "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." This perfectly describes BLASTX. So, (D) matches with (III).
(C) TBLASTX: The 't' stands for translated, and the 'x' for translation. This is the most computationally intensive version. It takes a nucleotide query, translates it in all six frames, and compares it against a nucleotide sequence database that is also dynamically translated in all six frames. So, it's a translated-vs-translated search. The description for this is in (IV): "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." So, (C) matches with (IV).
Step 3: Final Answer:
The correct matching is: (A)-(II), (B)-(I), (C)-(IV), (D)-(III). This corresponds to option (3).