Molecular genetics — identify the correct statement: Choose the one accurate statement about cDNA, restriction enzymes, RFLP, and protein sequence inference from nucleotide sequence (assume standard molecular biology practice and definitions).

Difficulty: Easy

Correct Answer: The amino acid sequence of a protein can be deduced from its corresponding cDNA nucleotide sequence

Explanation:


Introduction / Context:
Foundational concepts in molecular genetics include how cDNA relates to genes, what substrates restriction endonucleases recognize, where RFLPs commonly occur, and how protein sequences are inferred. This question checks precise understanding of these basics used across biotechnology and bioinformatics.



Given Data / Assumptions:

  • cDNA represents the reverse-transcribed, intron-free, mature mRNA sequence.
  • Conventional restriction endonucleases recognize palindromic sites in double-stranded DNA.
  • RFLPs reflect sequence variation at restriction sites, often in noncoding regions.
  • Standard genetic code enables translation of open reading frames from cDNA.


Concept / Approach:

To find the correct statement, match each claim against standard definitions. The only universally correct statement among the options is that cDNA, which mirrors spliced mRNA, can be translated in silico to deduce the encoded amino acid sequence of the protein.



Step-by-Step Solution:

Confirm cDNA lacks introns; thus intron size/sequence cannot be deduced from cDNA alone.Recall that classical restriction endonucleases act on double-stranded DNA; single-stranded cleavage is atypical and not a general rule.Note that RFLPs are frequently found in noncoding regions; they are not “usually formed” in coding regions.Use the genetic code to translate cDNA open reading frames and obtain the protein’s amino acid sequence — this statement is correct.


Verification / Alternative check:

Practical workflows (e.g., cloning a cDNA and Sanger sequencing) routinely translate cDNA to predict protein sequence and motif content; proteomics then validates peptides experimentally.



Why Other Options Are Wrong:

Introns from cDNA: cDNA is post-splicing; introns are absent.

Restriction enzymes on ssDNA: the canonical activity is on double-stranded DNA recognition sites.

RFLP location: commonly noncoding; coding regions are not the usual source.



Common Pitfalls:

Confusing genomic DNA (with introns) and cDNA (without introns), or overgeneralizing enzyme capabilities beyond their standard substrates.



Final Answer:

The amino acid sequence of a protein can be deduced from its corresponding cDNA nucleotide sequence

Discussion & Comments

No comments yet. Be the first to comment!
Join Discussion