Molecular Basis of Inheritance

E. coli cells with a mutated z gene of the lac operon cannot grow in medium containing only lactose as the source of energy because -

1. They cannot transport lactose from the medium into the cell
2. They cannot synthesize functional -galactosidase
3. In the presence of glucose, E. coli cells do not utilize lactose
4. The lac operon is constitutively active in these cells

Telomerase is an enzyme which is a -

1. RNA
2. Repetitive DNA
3. Simple protein
4. Ribonucleoprotein

Protein synthesis in an animal cell occurs -

1. On ribosomes present in the nucleolus as well as in cytoplasm
2. On ribosomes present in cytoplasm as well as in mitochondria
3. Only on the ribosomes present in cytosol
4. Only on ribosomes attached to the nuclear envelope and endoplasmic reticulum

Which one of the following makes use of RNA as a template to synthesize DNA -

1. Reverse transcriptase
2. DNA dependent RNA polymerase
3. RNA polymerase
4. DNA polymerase

During transcription holoenzyme RNA polymerase binds to a DNA sequence and the DNA assumes a saddle like structure at the point. What is the sequence called?

1. TATA box
2. GGTT box
3. CAAT box
4. AAAT box

Production of a human protein in bacteria by genetic engineering is possible because

1. The human chromosome can replicate in bacterial cell
2. The genetic code is universal
3. Bacterial cell can carry out the RNA splicing reactions
4. The mechanism of gene regulation is identical in humans and bacteria

During replication of a bacterial chromosome DNA synthesis starts from a replication origin site and

1. RNA primers are involved
2. is facilitated by telomerase
3. moves in one direction of the site
4. moves in bi-directional way

Which form of RNA has a structure resembling clover leaf ?

1. r-RNA
2. m-RNA
3. t-RNA
4. hn-RNA

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. UAUGC
2. TCTGG
3. UATGC
4. TATGC

The following ratio is generally constant for a given species :-

1. A+CT+G
2. G+CA+T
3. A+GC+T
4. T+CG+A