Q. No.Avery, MacLeod, and McCarty used DNase in their experiment because:
1.
It enabled them to isolate pure DNA samples.
2.
It enabled them to isolate pure protein samples.
3.
This allowed them to demonstrate that removing the DNA prevents transformation.
4.
It made sure that RNA will always be present when they attempted to transform the R strain.
What key observation regarding Garrod'sinborn of metabolism leads to a landmark discovery in molecular biology?
| 1. | Identification of a defective gene in individuals with alkaptonuria. |
| 2. | Identification of a defective gene in parents of alkaptonuria patients. |
| 3. | Identification of a defective enzyme in individuals with alkaptonuria. |
| 4. | Identification of the inheritance pattern of alkaptonuria as autosomal recessive. |
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. |
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 |
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. |
What would be the actual inducer for the lac operon?
| 1. | lactose | 2. | allolactose |
| 3. | ß-galactosidase | 4. | galactose |
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 |
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