Lecture 12: Bacterial Genetics

Question 1

what are mutations?

Answer 1

change of nucleotide sequence from a DNA level

Question 2

how do bacteria acquire genetic diversity?

Answer 2

evolution & adaptations

Question 3

horizontal communication

Answer 3

gene exchange

Question 4

vertical communication

Answer 4

new mutation is formed

Question 5

what is a mutant?

Answer 5

different genotype that carries the change

Question 6

are mutations heritable?

Answer 6

yes

Question 7

parental is the ( )

Answer 7

wild type

Question 8

replication error rate

Answer 8

10^-6 to 10^-7

Question 9

what 2 things increases mutation rate?

Answer 9

stresses & mutagens

Question 10

what are mutagens?

Answer 10

chemicals that induce mutation at higher rates than spontaneous rate

Question 11

what is the Ames test used for?

Answer 11

tests the ability of a chemical to induce revertant in an auxotroph

Question 12

auxotroph

Answer 12

bacteria that cannot synthesize histidine

Question 13

higher the number of colonies the ( ) the potenial

Answer 13

higher

Question 14

what are the 3 results of mutations?

Answer 14

1. neutral
2. beneficial
3. detrimental

Question 15

neutral result

Answer 15

no observable change

Question 16

beneficial result

Answer 16

gain function

Question 17

detrimental result

Answer 17

lost function

Question 18

what 2 results can occur from non-selectable mutation?

Answer 18

neutral & detrimental

Question 19

how can non-selectable mutations be found?

Answer 19

screening

Question 20

how do we screen for non-selectable mutation?

Answer 20

copy & pasting onto a plate using velvet to compare mutants

Question 21

point mutation

Answer 21

change in single base pair & mRNA

Question 22

silent mutation

Answer 22

substitution of 3rd base codon (neutral)

Question 23

missense mutation

Answer 23

substitution of 1st & 2nd base codon (change in amino acid sequence)

Question 24

nonsense mutation

Answer 24

amino acid change to a stop codon (detrimental)

Question 25

frameshift mutation

Answer 25

shifts 1 or 2 basepairs

Question 26

reversion

Answer 26

a second mutation can reverse the effect of a mutation

Question 27

revertant

Answer 27

wildtype phenotype

Question 28

true revertant

Answer 28

wildtype genotype

Question 29

transformation

Answer 29

uses free DNA as food

Question 30

conjugation

Answer 30

genetic transfer requiring cell to cell contact

Question 31

donor vs recipient

Answer 31

donor: plasmid +
recipient: plasmid -

Question 32

transduction

Answer 32

phages pick up host DNA & transfer into new host

Question 33

generalized transduction

Answer 33

random packaging of host DNA that creates a defective phage

Question 34

lytic phage

Answer 34

packages DNA randomly & does not induce a lytic cycle

Question 35

specialized transduction

Answer 35

not random packaging

Question 36

what type of phage does generalized transduction use?

Answer 36

defective

Question 37

what type of phage does specialized transduction use?

Answer 37

temperate

Question 38

phage conversion?

Answer 38

alteration of phenotype by prophages

Question 39

no prophage =?

Answer 39

no disease

Question 40

prophage +

Answer 40

pathogenic

Question 41

prophage -

Answer 41

harmless

Question 42

what are 2 examples of defense system that prokaryotes use?

Answer 42

programmed cell death & CRISPR

Question 43

what does CRISPR stand for?

Answer 43

cluster regularly interspaced short palindrome sequences

Question 44

adaptive immunity

Answer 44

resistance based on previous infections

Question 45

cas protein

Answer 45

degrades foreign DNA

Question 46

restriction enzymes

Answer 46

uses endonucleases

Question 47

phage exclusion

Answer 47

modified DNA to prevent replication