Chapter 6: Chromosome Mutations Flashcards

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1
Q

define aneuploidy

A

variations in a specific chromosome

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2
Q

define euploidy

A

complete haploid sets of chromosome are present

multiples of n

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3
Q

define polyploidy

A

more than two sets of chromosomes are present

more than 2 multiples of the haploid chromosome are found

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4
Q

nondisjunction is the…

A

disruption of the normal distribution of chromosomes into gametes

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5
Q

Monosomy is a type of _______ and is defined as the…..

A

aneuploidy

loss of one chromosome

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6
Q

haploinsufficiency

A

when a single recessive gene is insufficient to provide life-sustaining function for an organism

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7
Q

a trisomy is the

A

addition of a chromosome

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8
Q

autopolyploidy is the…

A

addition of one or more sets of chromosomes identical to the haploid compliment of the species

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9
Q

allopolyploidy is the…

A

combination of chromosome sets from different species

hybridization

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10
Q

what type of chromosomes aberrations change the total amount of genetic information in chromosomes?

A
  • deletions

- duplications

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11
Q

what type of chromosomes aberrations rearranges the genetic material but the information stays the same?

A

inversions

translocations

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12
Q

translocations occur between

A

nonhomologous chromosomes

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13
Q

terminal deletions occur…

A

near one end of the chromosome

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14
Q

intercalary deletions occur…

A

from the interior of a chromosome

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15
Q

a paracentric inversion…

A

does not include centromere

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16
Q

a pericentric inversion…

A

includes the centromere

17
Q

define alternate segregation

A

segregation pattern leading to a normal balanced gamete

18
Q

define adjacent segregation

A

segregation pattern leading to gametes containing duplications or deficiencies

19
Q

robertsonian translocation produces

A
  • normal
  • normal carrier
  • trisomy 21
  • lethal
20
Q

phenotypic variations result from

A

modifications at the chromosome level

21
Q

list 3 chromosomal modifications

A
  1. change in total chromosome number
  2. deletion or duplication of genes or chromosome segments
  3. rearrangements of genetic material
22
Q

nondisjunction in the first meiotic division results in

A

no normal zygotes

23
Q

nondisjunction in the second meiotic division results in

A

1/2 normal zygotes

24
Q

down syndrome critical region is found on which chromosome?

A

chromosome 21

25
Q

down syndrome occurs due to nondisjunction of

A

chromosome 21

26
Q

75% of nondisjunction of chromosome 21 occur during

A

meiosis 1

27
Q

what is the source of trisomy in 95% of cases?

A

the ovum

28
Q

which two human trisomies survive to term?

A
  • Patau syndrome
  • Edwards syndrome

occur at chromosome 13 & 18

29
Q

familial down syndrome is due to the translocation of…

A

the bottom part of chromosome 21 onto another chromosome

30
Q

chromosomal aberrations occur due to…

A

exposure to chemicals or radiation

31
Q

what condition results from the segmental deletion of chromosome 5?

A

cri du chat

32
Q

duplications may result in

A
  • gene redundancy
  • phenotypic variation
  • genetic variability
33
Q

gene amplification is a mechanism to

A

increase rDNA that codes for rRNA

34
Q

a crossover between paracentric inversion produces

A

dicentric chromatid and acentric chromatid

35
Q

what 2 segregation patterns result from translocation?

A
  • alternate segregation

- adjacent segregation

36
Q

define alternate segregation

A

leads to normal and balanced gametes

37
Q

define adjacent segregation

A

leads to gametes containing duplications and deficiencies