In Negative operon:
1.  Inducer binds with repressor
2.  Co-repressor does not bind with repressor
3.  Corepressor binds with inducer
4.  CAMP has a negative effect on the lac operon

Due to the discovery of which of the following in 1980, the evolution was termed as RNA world?

E. Coli about to replicate was placed in a medium containing radioactive thymidine for five minutes. Then, it was made to replicate in a normal medium. Which of the following observation shall be correct?

Types of RNA polymerase required in the nucleus for RNA synthesis:
1.  1
2.  2
3.  3
4.  4

Gene and cistron words are sometimes used synonymously because:
1.  One cistron contains many genes
2.  One gene contains many cistrons
3.  One gene contains one cistron
4.  One gene contains no cistron

mRNA is synthesized on a DNA template in which direction:
1.  5' → 3'
2.  3' → 5'
3.  Both
4.  Any

At the time of organogenesis, genes regulate the process at different levels and at different times due to:
1.  Promoter
2.  Regulator
3.  Intron
4.  Exon

A mutant strain of $T_4$ – Bacteriophage, R-II, fails to lyse the E-Coli but when two strains R- $I{I}^X$ and R-$I{I}^Y$ are mixed then they lyse the E.Coli. What may be the possible reason:
1.  Bacteriophage transforms in wild
2.  It is not mutated
3.  Both strains have similar cistrons
4.  Both strains have different cistrons

Which one of the following triplet codes, is correctly matched with its specificity for an amino acid in protein synthesis or as a 'start' or 'stop' codon:

1. UCG – Start

2. UUU – Stop

3. UGU – Leucine

4. UAC – Tyrosine

What would happen if in a gene encoding a polypeptide of 50 amino acids, the 25th codon (UAU) is mutated to UAA?