Question

4a. Define semi-conservative DNA replication. 4b. Explain why Recombinational Repair of thymidine dimers absolutely requires active DNA replication. 5a. Explain how the Ames Test works to identify whether a novel chemical (compared to water) is a DNA mutagen. b. Below, draw the plate results that would allow you to conclude that this novel chemical was in fact a mutagen compared to a plate with water as a negative control.

Answer 1

Q4 a) Ans Semiconservative DNA replication - During the process of DNA replication the two strands of nucleotides are seprate each strand form the template for free nucleottides to binds to the two identical daughter strands. each of which contains one origenal strande one Hewely synthesized strand 6) Ans Il Recombination repair is mechanism for I the generating a functional DNA molecule from two damaged molecules. repair process for dividing cell because replication fork arrive damaged site such as thymine dimer. before excision repair system bas damaged. when polymerase IT geaches thymine dimer', 'ddenine is mixing or added to growing istrand. However the belix distortion 'caused by weak dimer the hydrogen bond & dictivates the polymerase editing function of adenine is remořed Cycle begins again and again replication fork is fails.