Using reverse transcriptase or gene synthesis has an advantage over the shotgun approach in obtaining a copy of the gene required as:
1. | the gene produced can easily be ligated to the vector |
2. | the gene produced is not a split gene |
3. | the gene produced does not require a promoter to be expressed |
4. | the gene produced does not require an ori to replicate |
An RNA primer is essential for DNA synthesis carried out by DNA polymerase III. This is because, to synthesize DNA, DNA polymerase III requires:
1. | A free 3’ – PO4 group |
2. | A free 5’ – PO4 group |
3. | A free 3’ – OH group |
4. | A free 5’ – OH group |
For the multiplication of any alien piece of DNA in an organism it needs to be a part of a chromosome that has a specific:
1. | Telomeric sequence | 2. | Multiple cloning site |
3. | Ori | 4. | Selectable marker |
Identify the correct statements regarding a replisome:
I: | It is a complex of several proteins. |
II: | It includes enzymes like DNA polymerase, DNA helicase, and primase. |
III: | It is found at the replication fork during DNA synthesis. |
1. | I and II only | 2. | I and III only |
3. | II and III only | 4. | I, II, and III |
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. |
Study the results of the Meselson and Stahl experiment. What theoretically possible mode of DNA replication can be excluded after one round of replication?
1. | Conservative | 2. | Semiconservative |
3. | Disruptive | 4. | Both 1 and 3 |
Consider the following statements:
I: | The unequivocal proof of DNA being the genetic material was given by Hershey and Chase. |
II: | Meselson and Stahl proposed that DNA replication is semi-conservative. |
III: | Beadle and Tatum proposed the one -gene - one - enzyme hypothesis. |
Which of the above statements are true?
1. | I and II only | 2. | I and III only |
3. | II and III only | 4. | I, II, and III |
During DNA replication the leading and lagging strands are synthesized differently. The reason for this difference is:
1. | DNA polymerase can work only on one strand at a time |
2. | The single-strand binding proteins cannot bind to both strands of DNA |
3. | DNA ligase works only in the 3ʹ →5ʹ direction |
4. | DNA polymerase can add new nucleotides only to the 3’ end of a growing strand |
The origin of replication is a particular sequence in a genome at which replication is initiated. This region is AT-rich because:
1. | DnaA proteins bind to AT-rich sites. |
2. | DnaC proteins bind to AT-rich sites. |
3. | AT base pairs are more easily separated than GC base pairs. |
4. | AT base pairs contain more hydrogen bonds than GC base pairs. |
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