Explanation: Patients afflicted with a variant of Xeroderma pigmentosum, XP V are susceptible to developing skin cancer due to sun exposure. It is discovered that the gene encoding replicative polymerase Η.

Explanation: The polymerase Η was discovered in 1999, it is a member of family of DNA polymerases having the function of incorporating nucleotides opposite particular types of DNA lesions in the template strand.

Explanation: Translesion synthesis (TLS) polymerases have an unusually spacious active site for accommodating altered nucleotides that would not fit in other replicative enzymes.

Explanation: The translesion synthesis polymerases are only capable of incorporating one to a few nucleotides. They have no proofreading activity and also lack processivity.