quiz 4

Question 1

What are mutations?

Answer 1

any heritable changes in the DNA sequence of an orgnism

Question 2

Different forms of the same gene are called what?

Answer 2

Alleles

Question 3

Different alleles of the gene can exist in pairs, what are they?

Answer 3

Wild-type and the mutant allele

Question 4

Genotype?

Answer 4

the organism’s DNA sequence

Question 5

Phenotype?

Answer 5

the observable properties and or characteristics

Question 6

When do mutations occur?

Answer 6

when change is inherited

Question 7

a mutated gene product that is less active or is less produced is called what?

Answer 7

leaky

Question 8

If the gene product is inactive or the protein product is no longer expressed, it is called what?

Answer 8

null mutation

Question 9

Point mutation?

Answer 9

a single nucleotide base is replaced with another base, caused by mutagenic compound of errors in DNA replication

Question 10

What are two types of base pair changes?

Answer 10

Transition, purine replaced with another purine

Transversion, when the purine is replaced with a pyrimidine

Question 11

Silent mutation

Answer 11

results in the same amino acid, due to a wobble

Question 12

Missense

Answer 12

exchange of one amino acid for a different one

Question 13

nonsense

Answer 13

exchange of a coding amino acid for a stop codon resulting in truncated protein

Question 14

auxotrophic mutants

Answer 14

unable to produce a substance that is essential for growth, the original strain that is able to make the substance is called prototroph

Question 15

Catabolite mutants

Answer 15

unable to use a particular substance that the wild type can use for growth

Question 16

Mutations are ?

Answer 16

very rare

Question 17

Mutants help pinpoint genes that are involved in?

Answer 17

Common pathways

Question 18

Conditional-lethal mutants?

Answer 18

mutations that inactive essential genes, but are able to grow under certain conditions

Question 19

temperature-sensitive

Answer 19

the mutants proteins lose functionally as the temperature increase.

Question 20

cold sensitive

Answer 20

rare compared to mutants, include protein that form large complexes with other protein

Question 21

what type of mutants are able to grow in the presence of compounds that otherwise kill or inhibit wild-type strain?

Answer 21

Resistant Mutants

Question 22

What is positive selection?

Answer 22

mutants are easily selected for by growing cultures, in the presence of toxic substances, such as antibiotics or industrial toxin

Question 23

Mutations in the _____may allow protein to retain activity, but prevents the antibiotic streptomycin from binding to it is?

Answer 23

30s

Question 24

When can reversions occur?

Answer 24

if a mutation changes the sequence at the exact same location as the original mutation

Question 25

What is the Ames Test used for?

Answer 25

required for registration of new chemical products with FDA and the EPA

Question 26

What does the Ames Test determine?

Answer 26

determines the mutagenic or cancer-causing of chemical compounds based on reversion rates

Question 27

intragenic Vs intergenics

Answer 27

intragenic: Mutations occuring in the same gene but are at different locations Intergenic: mutations in separate gene product that is able to restore activity in a broken pathway

Question 28

suppression?

Answer 28

a second mutation | elsewhere in the genome that restores a mutant gene function

Question 29

nonsence?

Answer 29

changes the anticodon of tRNA

Question 30

spontaneous mutations?

Answer 30

mutations that can arise endogenously through errors in replication

Question 31

induced mutation?

Answer 31

exposing organisms to exogenous mutations to increase DNA damage

Question 32

what are deaminating agents?

Answer 32

hydroxylamine and nitrous acid, they remove amino groups from cytosine

Question 33

EMS alkylates?

Answer 33

causing them to be incorrectly copied

Question 34

Random mutagenesis?

Answer 34

exposing bacterial cells to mutagenic agents

Question 35

in Error-prone PCR, the fidelity of the TAQ polymerase is reduced by increasing

Answer 35

MgCl2 in the reaction, or using unequal concentrations of each nucleotide

Question 36

mutator strains

Answer 36

the plasmid carrying the gene of of interest is transformed into a mutator strain, such as XL1-RED

Question 37

What is XL1-RED

Answer 37

an e.coli strain deficient in DNA repair pathways causing it to make errors in DNA replication.

Question 38

Transposon?

Answer 38

a DNA sequence that can move from one place in aDNA to another with the help of transpose

Question 39

What is best used for mutagenesis in the lab?

Answer 39

Transposon mutagenesis

Question 40

What type of mutagenesis causes polar effect because of the presence of transcription termination ?

Answer 40

transposon mutagenesis

Question 41

What are the two types of transposition?

Answer 41

Replicative and conservative

Question 42

What is the Replicative transposition

Answer 42

new copy of the TE is generated, one is seen in the new site and other remains in the old site

Question 43

What is conservative transposon?

Answer 43

when the chromosome is integrated into the new site

Question 44

What is transposon ideal mutagenesis? (4) FISH

Answer 44

1. Transpose at high frequency 2. can inset in random sites 3. Easy selectable marker 4. broad host range

Question 45

What is a suicide vector?

Answer 45

where the transposon jumps on to any site on the plasmid

Question 46

ompF:::yfp is what color?

Answer 46

yellow

Question 47

ompC:::cyp is what color?

Answer 47

blue, it integrates into the chromosome

Question 48

What is directed mutagenesis?

Answer 48

introducing a mutation at predefined location, this allows the researchers to explore the function of the gene or alter the activity of an encoded protein.

Question 49

what are the two types of ways to get directed mutations

Answer 49

PCR, and DNA shuffling

Question 50

What are the limitation of mapping?

Answer 50

only tells the location of the mutation, but not the type of mutation very laborious