The difference between ATP and the nucleoside triphosphates used during DNA synthesis is that:
1. | The nucleoside triphosphates have the sugar deoxyribose; ATP has the sugar ribose. |
2. | The nucleoside triphosphates have two phosphate groups; ATP has three phosphate groups. |
3. | ATP contains three high-energy bonds; the nucleoside triphosphates have two. |
4. | ATP is found only in human cells; the nucleoside triphosphates are found in all animal and plant cells. |
Which of the following pairs of codons encode the same amino acid?
1. | AUG and AUC | 2. | UAA and UAC |
3. | GUA and GUG | 4. | UAG and UAC |
Griffith wanted to make a vaccine to prevent pneumonia. He injected heat-killed S-strain bacteria into the mice for this purpose. How can a killed bacteria help in making a vaccine?
1. | The heat-killed bacteria is a more potent toxin than the live one. |
2. | Protein denaturation due to heat changes the proteins of the bacterium. |
3. | Molecules from the cell surface are still intact and can provoke an immune response. |
4. | DNA molecules can transform other strains of bacteria. |
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 |