Telomere repetitive DNA sequences control the function of eukaryotic chromosomes because they:
1. act as replicons
2. are RNA transcription initiators
3. help chromosome pairing
4. prevent chromosome loss
During transcription, RNA polymerase holoenzyme binds to a gene promoter and assumes a saddle-like structure. What is its DNA-binding sequence?
1. | TIAA | 2. | AATI |
3. | CACC | 4. | TATA |
What would happen if in a gene encoding a polypeptide of 50 amino acids, 25th codon (UAU) is mutated to UAA?
1. | A polypeptide of 25 amino acids will be formed |
2. | Two polypeptides of 24 and 25 amino acids will be formed |
3. | A polypeptide of 49 amino acids will be formed |
4. | A polypeptide of 25 amino acids will be formed |
Gene regulation governing lactose operon of E. coli that involves the lac I gene products is:
1. | positive and inducible because it can be induced by lactose. |
2. | negative and inducible because repress or protein prevents transcription. |
3. | negative and repressible because repress or protein prevents transcription. |
4. | feedback inhibition because excess of β galactosidase can switch off transcription. |
Which of the following RNA should be most abundant in an animal cell?
1. | t-RNA | 2. | m-RNA |
3. | mi-RNA | 4. | r-RNA |
During DNA replication, Okazaki fragments are used to elongate:
1. | The lagging strand towards the replication fork. |
2. | The leading strand away from the replication fork. |
3. | The lagging strand away from the replication fork. |
4. | The leading strand towards the replication fork. |
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 |
Statement I: | The codon AUG' codes for methionine and phenylalanine. |
Statement II: | AAA' and 'AAG are both codons that code for the amino acid lysine. |
In light of the above statements, choose the correct answer from the options given below:
1. | Statement I is correct but Statement II is false. |
2. | Statement I is incorrect but Statement II is true. |
3. | Both Statement I and Statement II are true. |
4. | Both Statement I and Statement II are false. |
Identify the correct statement:
1. | The coding strand in a transcription unit is copied to an mRNA. |
2. | Split gene arrangement is characteristic of prokaryotes. |
3. | In capping, methylguanosine triphosphate is added to the 3' end of hnRNA. |
4. | RNA polymerase binds with the Rho factor to terminate the process of transcription in bacteria. |
During translation initiation in prokaryotes, a GTP molecule is needed in:
1. | Formation of formyl-met-tRNA |
2. | Binding of 30S subunit of the ribosome with mRNA |
3. | Association of 30 S-mRNA with formyl met-tRNA |
4. | Association of 50 S subunit of the ribosome with the initiation complex |