Griffith's experiment discovered bacterial transformation which in his experiment means:
1. | A mutation in the R strain made them virulent. |
2. | A mutation in the S strain made them non-virulent. |
3. | A rough strain passed genetic information to a smooth strain. |
4. | A smooth strain passed genetic information to a rough strain. |
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. |