Chapter 8 - Chromosome Variation

Question 1

aneuploidy

Answer 1

variation in chromosome number

Question 2

failure of homologous chromosomes in _______ or sister chromatids in _____

Answer 2

meiosis I; meiosis II

Question 3

animals are ______ of monosomies

Answer 3

intolerant

Question 4

animals are _____ of trisomies

Answer 4

tolerant

Question 5

trisomy 21

Answer 5

extra chromosome 21
caused by nondisjunction in ovum

Question 6

how does maternal age cause trisomy 21?

Answer 6

long delay between meiosis I and meiosis II

Question 7

patau

Answer 7

human trisomy
extra chromosome 13
50% death rate in first month

Question 8

edwards

Answer 8

human trisomy
extra chromosome 18
survival: 2-3 months

Question 9

warkany syndrome

Answer 9

human trisomy that is lethal in early embryo
extra chromosome 8

Question 10

polyploidy

Answer 10

individual in a diploid species has more than two multiples of the haploid number of chromosomes (3n,4n,5n…)

Question 11

autopolyploidy

Answer 11

whole set of chromosomes (3n,4n) are derived from parents that are related (same species)

Question 12

allopolyploidy

Answer 12

hybridization between closely related species (i.e- plants)

Question 13

colchicine

Answer 13

used to induce nondisjunction of chromosomes and polyploid function

Question 14

American cotton example

Answer 14

shows allopolyploidy between an Old World strain and a wild North American strain

allotetraploid

Question 15

tobacco example

Answer 15

shows allopolyploidy between two tobacco species

amphipolyploid

Question 16

protoplast

Answer 16

plant cells with cell walls removed

Question 17

endopolyploidy

Answer 17

cells in specific tissues may by polyploid in an otherwise diploid organism

Question 18

deletion

Answer 18

structural change

loss of a section of a chromosome

Question 19

cri-du-chat syndrome

Answer 19

deletion in humans

loss of one p arm on chromosome 5

Question 20

duplication

Answer 20

structural change

Question 20

duplication

Answer 20

structural change

sections of chromosomes occur in multiple copies

Question 21

cause of duplication

Answer 21

unequal crossing over

Question 22

gene amplification

Answer 22

genes that appear to be selectively duplicated

Question 23

inversion

Answer 23

structural change where a segment of a chromosome is removed, rotated 180 degrees, and replaced

requires 2 breaks

Question 24

paracentric

Answer 24

does not include centromere does not change length

Question 25

peircentric

Answer 25

includes centromere can change length

Question 26

crossing over in paracentric inversion loops produces _____

Answer 26

2 parental and two recombinant chromosomes

Question 27

dicentric

Answer 27

contains 2 centromeres and can form a bridge that breaks randomly

Question 28

acentric

Answer 28

lacks a centromere and drifts randomly

Question 29

results of crossing over in a pericentric inversion loop

Answer 29

nonparental chromosomes with deletions and duplications

Question 30

super genes

Answer 30

inversions can "lock in" favorable combinations of genes

Question 30

super genes

Answer 30

inversions can "lock in" favorable combinations of genes

Question 31

translocation

Answer 31

movement of chromosomal segments within or between chromosomes

Question 32

reciprocal translocation

Answer 32

two nonhomologous chromosomes exchange segments

Question 33

familial down syndrome

Answer 33

translocation in chromosomes 14 & 21

Question 34

fragile chromosomes

Answer 34

areas within chromosomes that have sites that could potentially break

Question 35

fragile sites in human genome

Answer 35

100+

Question 36

fragile x syndrome (Martin-Bell)

Answer 36

fragile sites affect phenotype; extra copies of CGG of FMR-1 gene on X mental retardation more likely in men

Question 37

number of repeats associated with expression of Fragile X

Answer 37

231+

Question 38

FHIT Gene

Answer 38

frgile area on chromosome 3 that is inherited through maternal line

Question 39

WWOX gene

Answer 39

on chromosome 16 encodes for tumor suppressor protein