Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Microbiology > Chapter 8 - Bacterial Genetics > Flashcards

Chapter 8 - Bacterial Genetics Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

How do bacteria adapt to changing environments?

A

Mutations and Horizontal gene transfer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Are bacteria haploid or diploid?

A

haploid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the three mechanisms of gene transfer?

A

Transformation, Transduction, and Conjugation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is transformation?

A

naked DNA uptake by bacteria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is transduction?

A

bacterial DNA transfer by bacteriophages

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is conjugation?

A

direct DNA transfer between bacterial cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Which mechanism is sensitive to deoxyribonuclease?

A

transformation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Which mechanism requires cell-to-cell contact?

A

conjugation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Can DNA without an origin of replication replicate?

A

NO

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are replicons?

A

plasmids, chromosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How are some DNA fragments added to chromosomes?

A

homologous recombination

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is generalized transduction?

A

any genes of donor cell are transferred

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is specialized transduction?

A

specific genes are transferred

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What cells are pathogenic in pneumococci?

A

Only encapsulated cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is special about the host cell in transformation?

A

The recipient cell must be competent

*some accept only from closely related bacteria (DNA sequence)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What kind of plasmids direct their own transfer in conjugation?

A

conjugative plasmids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the two types of conjugation?

A

Plasmid transfer and Plasmid + chromosome transfer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the process of plasmid transfer?

  • use the F plasmid of E. coli
    • F+ cells have, F- do not
A

1) pili bring cells into contact
2) enzyme cuts plasmid
3) single strand transferred
4) complementary strands synthesized
5) both cells are now F+

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the process of Chromosomal DNA transfer?

A

1) Hfr cells involved (high frequency recombination cells)
2) F plasmid is integrated into chromosome via homologous recombination
3) process is reversible

a) Hfr cell produces F pilus
b) transfer begins with genes on one side of origin of transfer of plasmid (in chromosome)
c) part of chromosome transferred to recipient cell
d) chromosome usually breaks before full transfer (~100 minutes)
e) recipient cell remains F- since incomplete F plasmid transferred

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the Start codon and amino acid?

A

AUG and Methionine (Met)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the Stop codons?

A

UAA, UAG, UGA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are the two major types of mutations?

A

Base substitution mutations and Addition/Deletion (frameshift)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the basis of base substitution mutations?

A

incorrect nucleotide/s incorporated during DNA synthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is a point mutation?

A

change of a single base pair

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What are the three possible outcomes of base substitution mutations?

A

Silent mutation, missense mutation, and nonsense mutation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is a silent mutation?

A

wild-type amino acid is still made

27
Q

What is a missense mutation?

A

Different amino acid or effect on protein depends upon role played by changed amino acid

28
Q

What is a nonsense mutation?

A

Specifies stop codon or nonsense codon and yields shorter protein

29
Q

What is a mutation called that inactivates a gene?

A

A null or knockout mutation

30
Q

Why are base substitutions more common in aerobic environments?

A

Reactive oxygen species (ROS) produced from O2 and can oxidize nucleobase guanine which DNA polymerase often mispairs with adenine

31
Q

What effects the outcome of Addition/deletion mutations?

A

the number of nucleotides involved

32
Q

What yields a frameshift mutation?

A

one or two nucleotide changes

33
Q

What does a frameshift mutation do?

A

results in a different set of codons translated and often results in a nonfunctional protein

34
Q

What does a three nucleotide change do?

A

adds or removes one amino acid and the impact depends on where the addition/deletion takes place

35
Q

What are transposons?

A
  • “Jumping genes”
  • can move from one location to another through a process called transposition
  • usually inactivates the gene to which it inserts
36
Q

Can transposons replicate independently?

A

NO

37
Q

Who discovered transposons and how did they study them?

A

Barbara McClintock and she observed color variation in corn kernels

38
Q

What are Spontaneous Mutations and how often do they occur?

A

Mutations that occur randomly at infrequent but characteristic rates
Rate = 10^-6 for a given gene
-mutations are passed to progeny

39
Q

What is it called when a mutation changes back to its original state?

A

Reversion

40
Q

What are induced mutations?

A

Mutations that result from outside influence

41
Q

What is the agent that induces mutation?

A

Mutagen

42
Q

What do mutagens do to the mutation rate?

A

increase it

rate = 10^-3

43
Q

What are the two general types of mutagens?

A

Chemical and radiation

44
Q

What does nitrous acid do?

A

Causes a nucleotide substitution by converting cytosine to uracil
-base pairs with adenine instead of guanine

45
Q

What do alkylating agents do?

A

Cause nucleotide substitutions by adding alkyl groups (CH3 and others) to nucleobases

  • nitrosoguanidine adds methyl group to guanine
  • -Changes GC to GT
46
Q

What do base analogs (5-bromouracil) do?

A

Cause nucleotide substitutions by being used in place of normal nucleobases in DNA
–resembles thymine and often pairs with cytosine

47
Q

What do intercalating agents (ethidium bromide) do?

A

Add or subtract nucleotides by inserting between base pairs

  • -push nucleotides apart, producing space and causes errors during replication
  • –likely carcinogen
48
Q

What do transposons do?

A

insertionally inactivate DNA by randomly inserting themselves

49
Q

What does UV light do?

A

Causes errors during repair process by creating intrastranded thymine dimers to form

  • -distorts molecules at the covalent bonding
  • –cells die if not repaired
50
Q

What do x-rays do?

A

Cause deletions by causing single and double-stranded breaks in DNA

  • -double stranded breaks often cause lethal deletions
  • -alter nucleobases
51
Q

What is non ionizing radiation?

A

UV

52
Q

What is ionizing radiation?

A

X-ray and Gamma ray

53
Q

What is the “Mobile Gene Pool”

A

plasmids found in most bacteria, archaea

  • some Eucarya
  • usually double stranded DNA with origin of replication
  • generally nonessential; cells can be cured
  • Few to thousands of genes
  • most have a narrow host range (single species)
  • some broad host range (include G- and G+)
  • one or a few or many per cell
54
Q

Which organisms have plasmid coded traits for antibiotic resistance?

A

E. coli, Salmonella sp, Neisseria sp, Staphylococcus sp, and Shigella sp

55
Q

Which organisms have plasmid coded traits for pilus synthesis?

A

E. coli, Pseudomonas sp

56
Q

Which organisms have plasmid coded traits for tumor formation in plants?

A

Agrobacterium sp

57
Q

Which organisms have plasmid coded traits for nitrogen fixation?

A

Rhizobium sp

58
Q

Which organisms have plasmid coded traits for Oil degradation?

A

Pseudomonas sp

59
Q

Which organisms have plasmid coded traits for Gas vacuole production?

A

Halobacterium sp

60
Q

Which organisms have plasmid coded traits for Insect toxin synthesis?

A

Bacillus thuringiensis

61
Q

Which organisms have plasmid coded traits for plant hormone synthesis?

A

Pseudomonas sp

62
Q

Which organisms have plasmid coded traits for antibiotic synthesis?

A

Streptomyces sp

63
Q

Which organisms have plasmid coded traits for Increased virulence?

A

Yersinia sp

64
Q

Which organisms have plasmid coded traits for toxin production?

A

Bacillus anthracis

Microbiology (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions