Exam 23: Mutations and Repair

Aـــــــــــــــــــــــ mutation has no effect on phenotype.

Mutations occur more frequently in hotspots.

When second site mutations change the mutant phenotype back to the wild type,this is calledــــــــــــــــــــــــ .

Terotogenic agentsــــــــــــــــــــ .

In some repair mechanisms,the parental DNA strand is used as a guide for repairing mistakes made in the newly synthesized DNA strand.The cell is able to distinguish the parental strand from the new strand because immediately following replication,the DNA isـــــــــــــــــــ .

Which of the following is notorious for causing covalent bonding of adjacent thymine residues in DNA?

Spontaneous mutations occurــــــــــــــــــــــــ .

A mutation that changes the orientation of a segment of DNA is called aan)ـــــــــــــــــــــــ.

Nonsense mutations occur whenـــــــــــــــــ is introduced into the coding sequence of a gene.

DNA polymerases often proofread their recently inserted nucleotides.

A ــــــــــــــــــــــmutation changes the coding sequence of the gene by inserting or deleting a single base pair.