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WVSOM -- Genetics
WVSOM -- Mutation
Question | Answer |
---|---|
Mutation | Any change in DNA sequence |
5 types of Silent Mutations | 3rd base of a wobbly codon Spliced out intron Spacer region of chromosome Similar amino acids Protein regions that aren’t critical |
5 types of Point Mutations | Transition Transversion Missense mutation Nonsense mutation Framesense mutation |
Mutant | entity with a mutation |
Wild type | nonmutated, found in nature |
Polyploidy | Triploidy |
5 examples of Chromosomal aberration | Deletion Insertion Duplication Translocation Inversion |
Spontaneous mutation | no known cause |
Induced mutation | Intentional mutanenesis |
Aneuploidy | Monosomy Trisomy |
Silent mutations | mutation with no effect |
What are point mutations? | Changing a few, usually one, base pairs |
Missense Mutation | altering one amino acid |
Nonsense Mutation | A premature stop codon producing a truncated polypeptide |
Frame shift mutation | Altering reading frame by insertion or deletion of sequence that is not a multiple of 3 By one insertion change the whole reading. |
Chromosomal Aberrations | Change in chromosome structure |
Deletion | Loss of sequence |
Insertion sequence | Gain of sequence |
Duplication | Copying sequence |
Translocation | Transfer of sequence |
Inversion | Flip flopped sequence |
Crossing over within inversion regions results in ____________ | Duplication and deletion of chromosome arms |
Chromosome3 Duplication-Deletion syndrome | Inversion |
Cri-du-chat syndrome | Deletion of chromosome 5 Microcephaly Wide eyes Severe mental retardation Cry of the Cat |
What is euploidy? | to possess complete sets of parental chromosomes |
Haploidy | one complete set |
diploidy | two complete sets |
polyploidy | more than two sets |
triploidy | three complete sets |
What is the genetic make up of down syndrome? | trisomy 21 |
What genetic make up is Edwards syndrome? | trisomy 18 |
Can kids with edward syndrome live? | no |
What is genetic make up of patau syndrome? | Trisomy 13 |
What are symptoms of Edward's Syndrome? | club feet overlapping fingers only a fraction survive to birth and most die by 1 week |
What is patau syndrome | central face deformities |
Turner Syndrome genetic problem | Monosomy XO All or part of the x chromosome is missing |
Symptoms of Turner Syndrome | physical abnormalities, such as short stature, lymphoedema, broad chest, low hairline, low-set ears, and webbed neck. |
Klinefelter syndrome genetic make up | XXy |
Klinefelter syndrome symptoms | gynamastia tall underdevelopment of sexual organs (testes) |
Extra sex chromosomes | XYY Normal phenotype Indistinctable from wild type |
What are endogenous mutagenic Processes? | naturally occuring within the cell |
What are DNA ligase errors? | chromosomal aberrations |
Examples of endogenous mutagenic processes | DNA ligase errors Unequal Crossing over Nondisjunction DNA Polymerase Infidelity Cytosome p-450 System Depurination Deamination Tautomeric Shifts |
mutagenic | ability to produce mutations |
mutagenesis | process of producing mutations |
mutagen | factor that produces mutations |
What are exogenous agents? | Environmental factors, from outside the body |
What is unequal crossing over? | instead of exchanging in the same place it is unequal downstream |
What is nondisjunction? | Aneuploidies During meiosis one of the chromosome pairs does not separate so two copies go to one cell and the other inherits nothing. |
What is cytochrome p-450 system? | hepatic detoxification system, osidizing hydrophobic compounds for excretion, activating some mutagens |
What is depurination? | purine excision |
What is deamination? | Excision of an amino group from A,C or G |
What are tautomeric shifts? | Transient changes in electron configuration of bases |
What are examples of exogenous mutagenic agents? | Radioactive Chemicals |
What is most common radioactive mutagen? | ultraviolet light |
What is ultraviolet light in terms of mutation? | low energy, electromagnetic radiation, sun light, excites ele trons, induces thymine dimers |
What are ionizing radiation in terms of mutagenesis? | Higher energy, alpha adn beta particles, x rays, excise electrons, and induce point mutations mostly |
What are gamma rays in terms of mutogenesis? | very high energy, electromagnet radiation, cleave chemical bonds and induce chromosomal aberrations. |
Chemical mutagens | alkylating agents strand cleavers base analogs intercalating agents insertional elements |
What are alkylating agents? | nitrogen mustard, add methyl or ethyl groups. interfere with replication and cause poitn mutations and chromosomal aberrations |
What are strand cleavers? | peroxides and sulfer compounds. React with phosphodiester bonds and create chromosomal aberrations |
Base analogs | bromouracil. mimic nucleotides and cause transition mutations |
What are intercalating agents | Proflavin. Wedge themselves into DNA and mimic a base pair. Stresses phosphodiester backbones resulting in DNA breaking |
Insertional Elements | viruses and traonsposons. jump in and otu of chromosomes, disrupt, add or delete sequence |
What is proofreading? | 3' - 5' exonuclease activity of the DNA replication apparatus |
What is DNA ligase? | This enzyme automatically joins any free 3' OH of one strand with a 5" phosphate of another. |
What is direct base repair? | enzymes that correct covalently damaged bases |
What is excision repair? | Specific enzymes that recognize base pair mistakes or covalently damaged nucleotides, and nick an adjacent strand. Then other enzymes excise the inapproprate base pairs and fill in the gap. |
What enzyme fills in gaps? | DNA Polymerase beta |
Natural selection question | will be given a scenario and must be able to recognize what is most likely the case where natural selection is teh cause. |