Genetics Exam 3 Flashcards
mutation that changes the mutant phenotype back into the wild type
Reverse mutation
mutation that alters the wild type phenotype
forward mutation
base substitution that results in a different amino acid
Missense mutation
mutation that changes a sense codon into a termination codon (severe mutation in protein function)
Nonsense mutation.
mutations generally impact?
the promotor, 5’ or 3’ noncoding sequences, splice junctions, and enhancers.
Chromatin structure and folding can impact?
gene function
mutation changes the codon but not the amino acid
silent mutation
missense mutatio alters the amino acid sequence but odes not change the function of the protein
Neutral
causes the complete or partial absence of a normal protein function. usually recessive
loss of function mutation
produces an entirely new trait or causes it to appear in an inappropriate tissue or at an inappropriate time
gain of function mutation
genetic change that hides or suppresses the effect of another mutation. can be Intragenic or Intergenic
Suppressor Mutation
occurs in the same gene as that containing the mutation being suppressed
Intragenic
…….
intergenic mutation
is Charge syndrome dominant or recessive if the affected patient is heterozygous?
Dominant
Charge Syndrome is a type of this mutation?
Nonsense-Codon CHD7 to a stop codon.
UUG codon codes for this amino acid?
Leucine
UAG is this type of codon
Stop codon
A base substitution that alters a single codon via insertion or deletion can result in?
a frameshift change
tri-nucleotide repeats can incorrectly produce a_____ on the newly synthesized strand causing part of the template……
Hairpin loop
Fragile X syndrome is a trinucleotide repeat of which codon?
CGG repeats
Huntington Disease is a type of trinucleotide repeat of this codon? Does it increase or decrease with generations?
CAG repeats. increase with generations and it gets worse.
addition of one or more nucleotides
insertion mutation
Spontaneous replication errors, spontaneous chemical …..
common mutation factors
if homologous chromosomes misalign during crossing over. what are the results?
one crossover contains an insertion. the other crossover contains a deletion.
Loss of a purine results in a nucleotide that cant pair. involving which bases?
A and G
Loss of an amine results in a biochemical change resulting in a different nucleotide replacing the original
methylcytosine…..
Thymine is a normal base and it’s mutagenic analog is?
5-Bromouracil
EMS is a classic chemical mutagen in which family?
alkylating agents
proflavin, acridine orange, and ethidium bromine are types of?
intercalating agents
Base analogs are mutatgenic bc of …..
they are similar in structure but not identical
name the four DNA repair mechanisms
Mismatch repair, direct repair, base-exclusion, and nucleotide-exclusion repair
in mismatched repair, the parent strand is methylated at GATC sequences……
……
concept check 3
C…..
what is Bloom Syndrome?
mutations in the gene encoding DNA helicase RecQ protein like-3 resulting in flaws in sister chromatid exchange.
Xeroderma pigmentosum
Autosomal recessive disease, photosensitivty, De Novo mutation not passed on in generation.
