CBSE
Multiple Choice QuestionsWhich one of the following does not follow the central dogma in molecular biology?
HIV
E.coli
Mucor
Chlamydomonas
Chlamydomonas
If the four bases of DNA have to code for twenty amino acids, the code should constitute a combination of bases. This was proposed by
Rosalind
Har Gobind Khorana
George Gamow
Marshall Nirenberg
Marshall Nirenberg
Assertion (a) In Eukaryotes, replication and transcription occur in the nucleus but translation occurs in the cytoplasm
Reasoning (R): mRNA is transferred from the nucleus to the cytoplasm where ribosomes and amino acids are available for protein synthesis
A is true but R is false
A is false but R is true
Both A and R are false
Both A and R are true but R is not the correct explanation for A
Both A and R are true but R is not the correct explanation for A
The variable number of tandem repeats' used as a probe in DNA fingerprinting is
Expressed sequence tag
Satellite DNA
Bacterial artificial chromosome
Restriction enzyme
Restriction enzyme
Expressed Sequence Tags (ESTs) refers to :
Polypeptide expression
DNA polymorphism
Novel DNA sequences
Genes expresses as RNA
Consider the statements regarding lac operon and choose the correct option
(i) lactose is the substrate for the enzyme beta-galactosidase and regulates switching on and off of the operon
(ii) lac operon consists of three regulatory genes
(iii) lac operon consists of one structural gene
(iv) regulation of lac operon by repressor is referred to as positive regulation.
(i) and (ii) only are correct
(iii) and (iv) only are correct
(i) only is correct
(iv) only is correct
(iv) only is correct
In Eukaryotes, the removal of RNA polymerase III from the nucleoplasm will affect the transcription of
mRNA
hnRNA
tRNA
5.8S rRNA
5.8S rRNA
Under which of the following conditions will there be no change in the reading frame of following mRNA?
5' AACAGCGGUGCUAUU 3'
Deletion of G from 5th position
Insertion of A and G at 4th and 5th positions respectively
Deletion of GGU from 7th, 8th and 9th positions
Insertion of G at 5th position
The 'terminator/stop codons UGA, UAG and UAA
Initiate translation
Do not code for any; amino acids
Code for only one amino acid
Code for more than one amino acid
Code for more than one amino acid
The scientists(s) who performed experiments with heavy isotopes of nitrogen to prove that DNA replicates semiconservatively is/are
Fredrick Griffith
Watson and Crick
Taylor
Meselson and Stahl
Meselson and Stahl
