Module 6: Microbial Genetics

Question 1

Mutation

Answer 1

Heritable change in the base sequence of a genome

Question 2

Wildtype Strain

Answer 2

Strain of an organism or virus obtained from natures; contains wildtype genome

Question 3

Mutant

Answer 3

Derived from the wildtype that carries a change in nucleotide sequence

Question 4

Genotype

Answer 4

Nucleotide sequence of an organism

Question 5

Phenotype

Answer 5

Observable properties of an organisms based on genotype

Question 6

Parental Strain

Answer 6

Strain (other than the wildtype strain) where the mutant strain is derived from

Question 7

Selectable Mutation

Answer 7

Confers advantage to the mutant under certain environmental conditions

Question 8

Auxotroph

Answer 8

Mutant strain with additional nutritional requirement for growth; unable to synthesize all of the vital nutrients.

Question 9

Prototroph

Answer 9

Can synthesize all the nutrients that are required for their growth from minimal medium without the addition of supplements

Question 10

Replica Plating Steps

Answer 10

1. Pick and transfer colonies from master plate onto a (i) Complete medium and (ii) Selective Medium
2. All colonies grow in (i) while mutants do not grow in (ii)
3. Compare the 2 plates

Question 11

3 Types of Mutations

Answer 11

1. Spontaneous Mutation: occurs without external intervention; error in base pairing replication
2. Induced Mutations: caused by agents in the environment or deliberate intervention by humans
3. Point Mutations: occurs when a single base-pair substitution takes place

Question 12

Gene Transfer in Bacteria (3)

Answer 12

1. Transformation - via environment
2. Transduction - via viruses
3. Conjugation - via sex pili

Question 13

Gene Transfer in Archaea cannot take place because of 2 reasons

Answer 13

1. Temperatures required to cultivate hyperthermophiles will melt agar
2. Most known antibiotics do not affect Archaea