Question

To study DNA replication, researchers often use bacteria that harbor a temperature sensitive mutation in one of the genes related to replication. This means that when cells are grown at lower temperatures (30°C) they are fine, but when shifted to 42°C the effect of the mutation becomes evident and that protein is no longer functional. Depending on the gene mutated, researchers observe that for some replication stops almost immediately, but for others more slowly. In this question you have a series of bacteria harboring temperature sensitive mutations in each the following genes. Mutations in which of the following TWO would most likely cause an immediate stop to replication? (Choose all that apply.] Sliding clamp DNA polymerase DNA ligase Single-stranded binding protein Replication initiator

Answer 1

Replication initiator are used to initiate replication while single stranded binding proteins prevent the single stranded of DNA to make duplex. ligase joined the okazaki fragment. All these will not stop replication immediately. But mutation in sliding clamps that moves DNA polymerase on DNA and DNA polymerase that adds nucleotides in growing strand will terminate replication immediately. So option A and B are correct