E. coli cells with a mutated z gene of the lac operon cannot grow in a medium containing only lactose as the source of energy because-
1. | They cannot synthesize functional beta-galactosidase |
2. | They cannot transport lactose from the medium into the cell |
3. | The lac operon is constitutively active in these cells |
4. | In the presence of glucose, E. coli cells do not utilize lactose |
Production of a human protein in bacteria by genetic engineering is possible because:
1. | Bacterial cells can carry out the RNA splicing reactions |
2. | The mechanism of gene regulation is identical in humans and bacteria |
3. | The human chromosome can replicate in bacterial cell |
4. | The genetic code is universal |
Which of the following exercises control over transcription:
1. Operator
2. Regulator
3. Promoter
4. Recon
Variations in proteins are due to:
1. Sequence of amino acids
2. Number of amino acids
3. R–group
4. None
A sequence of how many nucleotides in messenger RNA make a codon for an amino acid:
1. Four
2. One
3. Two
4. Three
DNA fingerprinting refers to:
1. | Analysis of DNA samples using imprinting devices |
2. | Techniques used for molecular analysis of different specimens of DNA |
3. | Techniques used for the identification of fingerprints of individuals |
4. | Molecular analysis of profiles of DNA samples |
During transcription, if the nucleotide sequence of the DNA strand that is being coded is ATACG, then the nucleotide sequence in the mRNA would be:
1. TCTGG
2. UAUGC
3. UATGC
4. TATGC
Number of base pairs in human chromosomes are:
1.
2.
3.
4.
The following ratio is generally constant for a given species:
1. | T + C / G + A | 2. | G + C / A+ T |
3. | A + C / T + G | 4. | A + G / C +T |
Initiation codon in eukaryotes is:
1. UGA
2. CCA
3. AGA
4. AUG