Which of the Following is Required for the Lambda Phage

Question

Which of the following is required for the lambda phage to cause lysis in a bacterial cell?
A) Precise excision of phage DNA from the host chromosome
B) Lambda integrase
C) Lambda excisase
D) All of these
E) None of these

Accepted Answer

All three of the options are required for the lambda phage to cause lysis in a bacterial cell. Firstly, the phage DNA must be precisely excised from the host chromosome by the lambda integrase enzyme. This is necessary to ensure that the phage DNA is no longer integrated into the host genome and can move on to the next stage of the lytic cycle. Next, the lambda excisase enzyme is required to initiate the lytic cycle and cause lysis of the bacterial cell, releasing the newly synthesized phages. Therefore, all three options (precise excision of phage DNA, lambda integrase, and lambda excisase) are necessary for the lambda phage to cause lysis in a bacterial cell.