Lab 9

Question 1

A mutation is _____ and ___ of organism

Answer 1

change in DNA sequence and genotype of organism

Question 2

ionizing radiation vs. nonionizing radiation?

Answer 2

ionizing radiation - short wave lengths
- can eject electrons from atoms or molecules
- directly damage DNA
Non-ionizing radiation - (UV radiation)
- wavelengths ranging from 40 - 390nm
- causes covalent bonds between thymine bases so it can not reproduce anymore.

Question 3

How does bacteria repair itself from UV?

Answer 3

DNA photolyase
- this enzyme splits thymine and thymine known as (light repair) or (photoreactivation)

Question 4

what are the mechanisms that do not have UV repair?

Answer 4

dark repair
- both base excision and mismatch repair activate when there are slight damage to DNA

Question 5

when there is significant DNA damage what repair is used?

Answer 5

SOS repair
damage DNA is removed
- adds nucleotides in a random fashion sometimes causing mutation