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16. The effect of nonsense mutation could be nullified by reversion as well as suppression. Which of the following processes will help to distinguish between the two kinds of revertants? […]

15. A hypothetical gene encodes a protein with the following amino acid sequence: Phe- Pro- Thr- Ala- Val-Arg- Ser A mutation of single nucleotide alters the amino acid sequence to […]

14. A gene encoding t-RNA undergoes a mutational event in its anticodon region that enables it to recognize a mutant nonsense codon and permit completion of translation. Such a mutation […]

13. Aspartic acid (Asp) is specified by the codon GAU and GAC. After mutation, Asp is changed to Alanine represented by GCX, where X may be A, U, C and […]

12. Mutation in gene ‘X’ leads to lethality in a haploid organjsm. Which one of the following is best suited to analyse the function of gene ‘X’? (1) Pleiotropic mutants […]

Spontaneity of mutation means (1) Mutation in absence of exogenous mutagen (2) Mutation directly proportion to presence of mutagen (3) Mutation inversely proportion to presence of mutagen (4) Mutation at […]

10. An insertion of single nucleotide in coding region of gene leads to frameshift mutation and result is formation of nonfunctional protein. Under certain condition second suppressor mutation in another […]

9. Consider the following DNA sequence 5’-ATGGGCATAGACGATATGGTAG-3’. Insertion of G between 3rd and 4th position lead to frameshift mutation and non-functional protein synthesis. Which intragenic suppressor mutation will have minimum […]

8. In a lac operon, a nonsense mutation in the gene encoding beta-galactosidase was found to interfere with the expression of downstream permease and transacetylase genes. Which one of the […]

7. An bacterial operon contains three structural genes A, B, and C in the same order. If polar mutation occurs in gene B, then the effect in protein would be […]