The primary RNA transcript in eukaryotes contains introns. This can be demonstrated by:
I: | A comparison of the DNA and mRNA sequences. |
II: | A comparison of the genomic DNA and cDNA sequences. |
III: | A hybridization between DNA and mRNA molecules. |
1. | I and II only | 2. | I and III only |
3. | II and III only | 4. | I, II, and III |
What would be true for the mutation that leads to sickle cell anemia ?
I: | Is a base substitution. |
II: | Is a deleterious mutation. |
III: | Is a missense mutation. |
1. | I and II only | 2. | I and III only |
3. | II and III only | 4. | I, II, and III |
Expression of the lac operon was completely repressed. This will lead to:
1. | The low level of lacZ, lacY, and lacA gene expression will continue. |
2. | Allolactose would accumulate within the cell and become toxic. |
3. | Lactose would not be converted into the inducer and the operon could not be induced. |
4. | The cell will not be able to use glucose as well. |
What type of changes will lead to a frameshift mutation?
I: | A transition | II: | A transversion | III: | A deletion of 3 bp |
1. | I and II only | 2. | III only |
3. | I, II, and III | 4. | None |
Identify the correct statements regarding mutations:
I: | Are permanent changes in the DNA sequence or structure. |
II: | Produce allelic variation. |
III: | Are more likely to be harmful than beneficial. |
1. | I and II only | 2. | I and III only |
3. | II and III only | 4. | I, II, and III |
Regulation of gene expression very commonly involves transcriptional regulation. The most important significance of this is that it:
1. | is highly efficient at completely preventing transcription. |
2. | allows the cell to only produce proteins that are needed at the time. |
3. | can be induced by a repressor protein. |
4. | can be done only in prokaryotes. |
What would be the actual inducer for the lac operon?
1. | lactose | 2. | allolactose |
3. | ß-galactosidase | 4. | galactose |
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. |
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 |
T2 bacteriophage was used by Hershey and Chase to conclusively prove that DNA and not protein is the genetic material because:
1. | It makes capsomeres with the help of its genes. |
2. | It injects its genetic material into a bacterial cell. |
3. | It can undergo either the lytic or lysogenic life cycle |
4. | It enters the bacterial cell to cause infection. |