BICH 431 Exam 1 Terms Questions
with Complete Answers
failure to complement - ANSWER-two genotypes are combined and they don't give a
wt phenotype
haplosufficient - ANSWER-complete loss of function with mutation
haploinsufficient - ANSWER-in WT function is still not complete
complementation in Drosophilia experiment - ANSWER-determined that different eye
colors were all mutants were in the white gene
W+ is ABD transporter of pigment
why do molecular geneticists care about mutants? - ANSWER-understand function
of each specific gene
changing one thing at a time
spontaneous mutations - ANSWER-replication errors
DNA damage
transposable elements
replication errors - ANSWER-DNA polymerase error
DNA damage that doesn't get repaired before replication fork hits that area
after proof reading, only 1 in 10 billion bases is wrong
nonsense mutation - ANSWER-causes DNA that coded for an amino acid to code for
nothing (stop codon)
results in truncated protein
missense mutation - ANSWER-causes DNA to code for a different amino acid than it
is supposed to
silent mutation - ANSWER-doesn't actually change an amino acid, just the code
frameshift mutation - ANSWER-insertion, deletion, etc.
causes a different amino acid and will result in a truncated protein
null - ANSWER-complete loss of function
gain of function - ANSWER-normal function is faster or better
new function may be added
loss of function - ANSWER-partial loss of function or slower reaction rate
, conditional mutation - ANSWER-sensitive to environment, temp sensitive is common
synthetic mutation - ANSWER-need more than one mutation in the same gene to
see a phenotype
point mutation - ANSWER-(how mutation behaves genetically)
-change in single nucleotide
-transition or transversion
transition - ANSWER-purine to purine (A-G) or pyrimidine to pyrimidine (C-T)
(how mutation behaves genetically)
transversion - ANSWER-purine to pyrimidine or vice versa
(how mutation behaves genetically)
true revertant mutation - ANSWER-new mutation in the same spot switches original
mutation back to wild type
(how mutation behaves genetically)
second-site suppressor revertant mutation - ANSWER-new mutation at different
position now gives wild type function; suppresses phenotype of original mutation
(how mutation behaves genetically)
cis-acting mutation - ANSWER-mutations need to be physically linked
in the same gene as the original mutation
(how mutation behaves genetically)
trans-acting mutation - ANSWER-second mutation in a different gene
(e.g. multimeric complex)
(how mutation behaves genetically)
directed mutagenesis (categories) - ANSWER--point mutations
-gene fusions
-gene knockouts
random mutagenesis (categories) - ANSWER--forward genetics
reverse genetics
common mutagens - ANSWER-chemical (ethyl methanesulfonate)
radiation (x-ray, gamma, neutron)
insertional (transfer DNA, transposons)
strategy of forward genetics - ANSWER-1. mutagenize wt and screen for abherrant
pheno
2. identify gene sequence of mutant
3. analyze function of gene
*unbiased approach*
with Complete Answers
failure to complement - ANSWER-two genotypes are combined and they don't give a
wt phenotype
haplosufficient - ANSWER-complete loss of function with mutation
haploinsufficient - ANSWER-in WT function is still not complete
complementation in Drosophilia experiment - ANSWER-determined that different eye
colors were all mutants were in the white gene
W+ is ABD transporter of pigment
why do molecular geneticists care about mutants? - ANSWER-understand function
of each specific gene
changing one thing at a time
spontaneous mutations - ANSWER-replication errors
DNA damage
transposable elements
replication errors - ANSWER-DNA polymerase error
DNA damage that doesn't get repaired before replication fork hits that area
after proof reading, only 1 in 10 billion bases is wrong
nonsense mutation - ANSWER-causes DNA that coded for an amino acid to code for
nothing (stop codon)
results in truncated protein
missense mutation - ANSWER-causes DNA to code for a different amino acid than it
is supposed to
silent mutation - ANSWER-doesn't actually change an amino acid, just the code
frameshift mutation - ANSWER-insertion, deletion, etc.
causes a different amino acid and will result in a truncated protein
null - ANSWER-complete loss of function
gain of function - ANSWER-normal function is faster or better
new function may be added
loss of function - ANSWER-partial loss of function or slower reaction rate
, conditional mutation - ANSWER-sensitive to environment, temp sensitive is common
synthetic mutation - ANSWER-need more than one mutation in the same gene to
see a phenotype
point mutation - ANSWER-(how mutation behaves genetically)
-change in single nucleotide
-transition or transversion
transition - ANSWER-purine to purine (A-G) or pyrimidine to pyrimidine (C-T)
(how mutation behaves genetically)
transversion - ANSWER-purine to pyrimidine or vice versa
(how mutation behaves genetically)
true revertant mutation - ANSWER-new mutation in the same spot switches original
mutation back to wild type
(how mutation behaves genetically)
second-site suppressor revertant mutation - ANSWER-new mutation at different
position now gives wild type function; suppresses phenotype of original mutation
(how mutation behaves genetically)
cis-acting mutation - ANSWER-mutations need to be physically linked
in the same gene as the original mutation
(how mutation behaves genetically)
trans-acting mutation - ANSWER-second mutation in a different gene
(e.g. multimeric complex)
(how mutation behaves genetically)
directed mutagenesis (categories) - ANSWER--point mutations
-gene fusions
-gene knockouts
random mutagenesis (categories) - ANSWER--forward genetics
reverse genetics
common mutagens - ANSWER-chemical (ethyl methanesulfonate)
radiation (x-ray, gamma, neutron)
insertional (transfer DNA, transposons)
strategy of forward genetics - ANSWER-1. mutagenize wt and screen for abherrant
pheno
2. identify gene sequence of mutant
3. analyze function of gene
*unbiased approach*
