4. Following observations were made about tRNA.
A. tRNA encoding genes cluster at specific regions of the human genome
B . 5′ end of the mature tRNA is generated by RNAse P mediated cleavage
C. Modified bases may confer increased stability to Trna
D. Modified bases of tRNA do not affect the pattern of wobble pairing
E. Suppressor tRNAs compete with the release factors to read the termination codons
Which one of the following combinations of statements represents correct observations?
(1) A, C, E    (2) B, E, D
(3) B, C, E    (4) A, B, D

Correct Observations About tRNA: Genomic Clustering, Processing, and Function

Introduction

Transfer RNA (tRNA) is essential for translating genetic information into proteins. Its genes, processing, and modifications have been thoroughly studied, revealing unique features in the human genome and in cellular function. This article examines several key observations about tRNA, clarifies which are correct based on current scientific understanding, and explains the significance of each, especially for students and researchers in molecular biology.

Review of the Observations

Let’s evaluate each statement about tRNA:

A. tRNA encoding genes cluster at specific regions of the human genome
B. 5′ end of the mature tRNA is generated by RNAse P mediated cleavage
C. Modified bases may confer increased stability to tRNA
D. Modified bases of tRNA do not affect the pattern of wobble pairing
E. Suppressor tRNAs compete with the release factors to read the termination codons

Detailed Analysis of Each Statement

A. tRNA Encoding Genes Cluster at Specific Regions of the Human Genome

InCorrect.
tRNA genes is not cluster in the genome

B. 5′ End of the Mature tRNA is Generated by RNAse P Mediated Cleavage

Correct.
During tRNA maturation, the precursor tRNA transcript undergoes precise cleavage at the 5′ end by the enzyme RNAse P, generating the mature tRNA’s 5′ terminus. This is a fundamental step in tRNA processing and is conserved across all domains of life910.

C. Modified Bases May Confer Increased Stability to tRNA

Correct.
tRNA molecules contain numerous modified nucleotides, such as pseudouridine and dihydrouridine, which are known to enhance their stability, folding, and function. These modifications protect tRNA from degradation and help maintain the correct three-dimensional structure necessary for efficient translation910.

D. Modified Bases of tRNA Do Not Affect the Pattern of Wobble Pairing

Incorrect.
This statement is not accurate. Modified bases in tRNA, especially at the wobble position (position 34), can significantly influence wobble pairing, sometimes expanding or restricting the range of codons a tRNA can recognize. Thus, modifications do affect the pattern of wobble pairing910.

E. Suppressor tRNAs Compete with the Release Factors to Read the Termination Codons

Correct.
Suppressor tRNAs are mutant tRNAs that can recognize stop codons and insert an amino acid instead of allowing translation to terminate. These tRNAs compete with release factors at the ribosome, which would normally recognize stop codons and end protein synthesis910.

Correct Combination: B, C, and E

Based on the above analysis, the correct set of observations is:

• B. 5′ end of the mature tRNA is generated by RNAse P mediated cleavage

• C. Modified bases may confer increased stability to tRNA910

• E. Suppressor tRNAs compete with the release factors to read the termination codons910

Thus, the correct answer is: (3) B, C, E

Related Search Keywords Explained

• RNAse P: The enzyme responsible for cleaving the 5′ leader sequence from pre-tRNA.

• tRNA modifications: Chemical changes to tRNA bases that affect stability and function.

• Suppressor tRNA: A tRNA variant that can override stop codons.

• Wobble pairing: Flexibility in base pairing at the third codon position, influenced by tRNA modifications.

Summary Table

Conclusion

tRNA biology is rich with structural and functional diversity. The correct observations—clustering of tRNA genes, the stabilizing effect of modified bases, and the ability of suppressor tRNAs to compete with release factors—reflect both the complexity and precision of the translation process. Understanding these features is vital for anyone studying molecular genetics or protein synthesis.

Correct answer:
(3) B, C, E