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28 Cards in this Set
- Front
- Back
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what is a chromosome mutation
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change in number or structure of chromosomes
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5 types of chromosome mutations
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deletion
extra chromosome duplication inversion translocation |
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define euploid
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multiple of basic chromosome set
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define polyploidy
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more than 2 sets of chromosomes
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is polyploidy more common in plants or mammals
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plants; increasing polyploidy = larger cell size
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define autopolyploid and how it arises
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multiple chromosome sets within the SAME species
-cytokinesis fails to occur at end of mitosis |
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define allopolyploid and how it arises
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multiple chromosome sets as a result of hybridization
-results from hybridization |
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what is aneuploid? define nullisomy, monosomy, trisomy
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-chromosome number that is not multiple of haploid number
N: missing a pair of chromosomes M: missing one chromosome T: extra chromosome |
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How does Monosomy arise
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normal gamete and gamete lacking a chromosome form a union
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how does trisomy arise
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normal gamete and gamete with extra chromosome form a union
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what are monosomy syndromes
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usually non-viable
-Turner Syndrome (XO) females, sterile learning deficiencies, webbed neck |
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what are trisomy syndromes
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Sex: XXX, XXY (Klinefelter), XYY
Autosomal -Downs (21), caused by females, increases with age -13 and 18, but death at early age |
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are plants or mammals more tolerant of aneuploidy
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plants
-creates distinct phenotypes |
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why does aneuploidy create such abnormal phenotypes
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gene dosage problem
-individuals with missing or extra chromosomes will have gene dosage problem |
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what is a deletion
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loss of part of chromsome
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what is a syndrome most known from deletions
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Cri-du-Chat
-deletion of tip of short arm of chromosome 5 -cat-like mewing sound from infants |
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what is a deletion heterozygote; what occurs during meiosis/matching
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one member of chromosome is normal, the other contains a deletion
-a loop is created by normal chromosome b/c it has nothing to match with |
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what is pseudodominance
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occurs in deletion heterzygotes
-when normal chromosome has recessive allele where deletion chromosome has no allele |
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what is duplication
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extra copy of a chromosomal segment
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what are 3 types of duplications
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tandem: adjacent
insertional: located somewhere else in genome segmental: larg duplicated units |
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what occurs in yeast w/ respect to duplications
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duplications arise as a result of ancestral polyploidy
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define inversion
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chromosomal segment is taken out, flipped around, and placed back in chromosome
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different btwn paracentric and pericentric inversion
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para: EXCLUDES centromere
peri: INCLUDES centromere |
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what products are formed from paracentric inversions
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deletion products
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what products are formed from pericentric inversions
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duplication-deletion products
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define translocation; what is key point of translocation
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segment from one chromosome is detatched and reattached to a different chromosome
-no genetic info gained/lost |
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what is reciprocal translocation
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two non-homologous chromosomes trade pieces
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what shape is formed from heterozygotes for reciprocal translocation during meiosis I
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cross-shape
-half of products of meiosis are non-viable |
