10.2

Question 1

what are the types of chromosome number variations?

Answer 1

aneuploidy (change in number of INDIVIDUAL chromosomes)
polyploidy (change in number of SETS of chromosomes)

Question 2

what is the difference between ___somy and ___ploidy?

Answer 2

somy - number of particular chromosomes
ploidy - total number of chromosomes

Question 3

what the most common types of aneuploidy in diploids (2n)?

Answer 3

nullisomy (lose both)
monosomy (lose one)
trisomy (gain one)
tetrasomy (gain both)

Question 4

what is double-monosomic?

Answer 4

lose two non-homologous chromosomes

Question 5

what is double trisomic?

Answer 5

gain two non-homologous chromosomes

Question 6

how does aneuploidy occur?

Answer 6

nondisjunction and deletions of centromeres

Question 7

what is nondisjunction?

Answer 7

failure of homo chromosomes or sister chromatids to seperate

Question 8

what is the outcome of non-disjunction?

Answer 8

trisomy - may be viable
monosomy - only viable for sex chromosomes

Question 9

what is Turner syndrome?

Answer 9

monsomy X

Question 10

what is klinefelter syndrome?

Answer 10

extra copies of X

Question 11

what is edwards syndrome?

Answer 11

trisomy 18

Question 12

what is patau syndrome?

Answer 12

trisomy 13

Question 13

what is primary down syndrome?

Answer 13

trisomy 21
most common type
usually random non-disjunction in mom

Question 14

what is familial down syndrome?

Answer 14

extra chromosome 21 is attached to another chromosome (14 or 15 usually)
3-4% of cases

Question 15

how does familial down syndrome happen?

Answer 15

parent carries chromosome that underwent robertsonian translocation (exchange of long arms of non-homologous acrocentric chromosomes)

Question 16

what are the most frequent trisomies?

Answer 16

higher number (or sex) chromosomes - more viable because less genetic information

Question 17

is aneuploidy tolerated in plants?

Answer 17

yes - much better than in humans

Question 18

where is polylpoidy found?

Answer 18

sometimes in fish, reptiles, amphibians, invertebrates
not found in mammals and birds
very important and common in plants

Question 19

what are the two types of polyploidy?

Answer 19

autopolyploidy - multiples of same genome
allopolyploidy - multiples of closely related genomes (different species)

Question 20

where does polyploidy come from?

Answer 20

nondisjunction in mitosis or meiosis

Question 21

what produces autotetraploidy?

Answer 21

nondisjuction of all chromosomes in mitosis in early embryo

Question 22

what causes diploid gametes?

Answer 22

nondisjunction of all chromosomes during meiosis

Question 23

what causes autotriploid?

Answer 23

diploid gamete + normal gamete

Question 24

what causes autotetraploid?

Answer 24

diploid gamete + diploid gamete

Question 25

what are the effects of autopolyploidy?

Answer 25

usually sterility (odd numbered ploidy)
most are genetically unbalanced

Question 26

how do you make sterile hybrid plants fertile?

Answer 26

double the genome by mitotic non-disjunction (make allopolyploids)

Question 27

what is the significance of polyploids in agriculture?

Answer 27

bigger fruits
seedless (sterile)
ei: bananas and strawberrys

Question 28

what are the cons of polyploids in agriculture?

Answer 28

no evolution or natural selection, cannot adapt to new conditions