Microbiology Test Questions with Answers

 Question 1
Needs Grading

An organism with a mutation that is no longer able to make a particular nutrient for itself is known as a(n) _________________.

Selected Answer:
[None Given]
Correct Answer:

auxotroph

 Question 2
Needs Grading

An organism that has a mutation is called a(n)______________.

Selected Answer:
[None Given]
Correct Answer:

mutant

 Question 3
1 out of 1 points

Which of the following causes extra nucleotides to be added to a gene?

Selected Answer:

insertion mutation

 Question 4
1 out of 1 points

Which of the following have chemical structures similar to nitrogenous bases?

Selected Answer:

base analogs

 Question 5
Needs Grading

In complete sentences, discuss repair mechanisms of thymine dimers. Be sure to describe all three mechanisms, light repair, dark repair, and SOS repair

Selected Answer:
[None Given]
Correct Answer:

Light repair-sunlight energy is used to fuel and enzyme that breaks the bond between adjacent thymines(1pt). -Only works in daylight (1pt)
Dark repair-enzyme cuts out the piece of DNA containing the thymine dimer (1pt) DNA polymerase must come make two new thymines (1pt)
SOS repair- only used after heavy UV light damage when there are multiple thymine dimers (1pt) Set of 20 genes are turned on; one is for a new DNA polymerase which can read past the thymine dimer but does not have proof reading capability (1pt)

 Question 6
Needs Grading

In complete sentences describe the technique used to select auxotrophic mutants in lab. Be sure to include the procedure for indirect selection/replica plating.

Selected Answer:
[None Given]
Correct Answer:

Indirect selection./replica plating-use sterile velvet (1) to move bacteria to a NA plate and a NA + nutrient plate. (1) Incubate and