CH16 Flashcards

(38 cards)

1
Q

total genetic potential of MO, code in its DNA

A

gene

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

the DNA that is expressed by the MO under a given set of conditions

A

phenotype

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

change in nucleotide sequence, may result in change of protein

A

mutation

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

types of mutations

A

mutant/wild type
spontaneous
induced

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

product of the standard “normal” allele at a locus, in contrast to that produced by a non-standard, “mutant” allele

A

wild type mutation

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

errors that lead to changes in DNA

A

spontaneous mutation

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

exposed to chemical or physical agent

A

induced mutation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q
  • damage DNA
  • alter DNA chemistry
  • interfere with repair mechanism
A

mutagen

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

point mutations can be

A

silent
missense
nonsense

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q
  • AAU–>AAC
  • both code for same AA
  • protein unaltered
  • no consequence for organism
A

silent point mutation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q
  • GAG–>GUG
  • AA is different
  • significant but not always deadly
  • sickle cell anemia
A

missense point mutation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q
  • UAU–>UAA
  • stops instead of AA
  • non functional product protein fragment
A

nonsense pont mutation

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

insertion or deletion of nucleotide

A

frameshift mutations

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

describe the Ames Test

A
  • The Ames test is based on the observation that many carcinogens also are mutagens.
  • The test determines if a substance increases the rate of mutation; that is, if it is a mutagen. If the substance is a mutagen, then it is also likely to be carcinogenic if an animal is exposed to it at sufficient levels
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what was Bruce Ames procedure for his experiment with histidine + Salmonella

A
  • had culture of Salmonella histidine auxotroph and added it to a plate with complete medium and small amount of histidine (control) and to a plate that had medium with test mutagen and small amount of histidine
  • incubated at 37 degrees C for a day or two
  • the control plate had spontaneous revertants and the other had revertants induced by the mutagen
  • if numbers are larger on mutant plate than control, then the revertants are induced by mutagen
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

why add liver enzymes to the Ames test?

A

alfotoxins (produced by fungus) are mutagenic when broken down and makes results more accurate

17
Q

exchange/combining of genetic material from two organisms

A

recombination

18
Q

recombination in eukaryotes and prokaryotes

A

-eukaryotes
diploid; crossing over b/t chromosome pairs (meiosis)
-prokaryotic
transfer of pieces of DNA from a donor bacterium to recipient (another bacteria)
incorporate into recipient DNA

19
Q

mechanisms of DNA transfer

A

conjugation
transformation
transduction

20
Q

cell to cell contact, depends on presence of plasmids

21
Q

recipient bacterium takes up “free-floating” DNA

A

transformation

22
Q

bacterial virus (phage) transfers DNA from donor to recipient

23
Q

small pieces of extra DNA

24
Q

how are plasmids independent of host chromosome

A
  • can be eliminated (hi temp, starvation)
  • multiple copies
  • some can integrate with chromosome (episome)
25
genes for pili sex (conjugation)
fertility F plasmids
26
antibiotic resistance genes
R plasmids
27
toxin genes
virulence plasmids
28
- genes to degrade pesticides (Sutamonas sp) | - N2 fixation (Ribosium bacteria)
metabolic plasmids
29
Lederburg and Tatum experiment
- used triple mutants - positive, mixture and negative strains in tubes - positive and negative tubes had no spontaneous generation on plates - mixture plate had bacteria that synthesized all 6 - conclusion: must be genetic change in bacteria
30
Davis experiment
- "U tube" experiment - positive and negative strains were separated by a fritted glass filter - filter does not allow bacteria to move, avoids cross feeding, no cells pass but media and nutrients, - mixes back and forth from pressure/suction - conclusion: cells need to interact to be phototrophs
31
describe F+ by F+ mating
- transfer of plasmid and gene - F+ pillus connects to F- cell - conjugation bridge forms, origin of transfer pulls of a strand of DNA and nuclease binds to origin of transfer - F- cell translates new strand (plasmid from F+) and becomes F+, which means it can conjugate with other cells
32
describe Hfr by F- mating
- most DNA transferred - plasmid incorporated into host chromosome (Hfr) - pillus connects Hfr to F- by forming conjugation bridge - little bit of plasmid and chromosome gene transferred into cell recipient(F-) - donor DNA replicated by rolling circle method and transferred - donor remains unchanged and recipient loses plasmid; donor DNA incorporated into recipient chromosome(F-) - F- cell is genetically distinct from original
33
Griffith's transformation experiment
- heat-killed smooth pneumococci with capsule - > mouse lives - live, virulent, smooth pneumococci, with capsule - >mouse dies - live, nonvirulent, rough, pneumococci, no capsule - >mouse lives heat-killed smooth pneumococci with capsule + live, nonvirulent, rough, pneumococci, no capsule = Live, smooth, pneumococci, with capsule PLUS live, rough, pneumococci, no capsule isolated from dead mouse conclusion: must have picked up trait (floating DNA) to form capsule (transformation)
34
one complex mRNA with numerous ribosomes attached to produce lots of proteins in short amount of time
polyribosome
35
describe transformation with DNA (chromosome) fragments
-bacterial chromosome uptakes SS of DNA and either integrates by nonreciprocal recombination (stable transformation) or degradation (unsuccessful transformation)
36
describe transformation with a plasmid
-bacterial chromosome uptakes the plasmid and doesn't incorporate it into its DNA (stable transformation)
37
describe transduction
-phage attaches and causes destruction of host DNA -synthesis of viral DNA and coat proteins -virus capsid protein synthesis and virus assembly -lysis of cell with release of phage particles and subsequent infection of another cell -phage recognizes and binds to new cell causes either: -integration of donor DNA into recipient chromosome (stable gene transfer) -degradation (unsuccessful gene transfer) -survival of donor DNA (abortive transduction)
38
ability to pick up DNA fragments
competent cells