Which of the following is not required in the preparation of a recombinant DNA molecule?
1. Restriction endonuclease
2. DNA ligase
3. DNA fragments
4. E. coli
The role of DNA ligase in the construction of a recombinant DNA molecule is
1. | formation of phosphodiester bond between two DNA fragments |
2. | formation of hydrogen bonds between sticky ends of DNA fragments |
3. | ligation of all purine and pyrimidine bases |
4. | None of the above |
A bacterial cell was transformed with a recombinant DNA that was generated using a human gene. However, the transformed cells did not produce the desired protein. Reasons could be:
1. | human genes may have intron which bacteria cannot process |
2. | amino acid codons for humans and bacteria are different |
3. | human protein is formed but degraded by bacteria |
4. | All of the above |