Quiz 2

Question 1

What are the three types of chromosomal mutations?

Answer 1

aneuploids
chromosome rearrangement
polyploids

Question 2

aneuploids

Answer 2

alter the number of chromosomes

Question 3

chromosome rearrangement

Answer 3

alter chromosome structure
duplication, deletion, inversion, translocation

Question 4

polyploids

Answer 4

one or more additional sets of chromosomes

Question 5

non-disjuction

Answer 5

failure of homologous chromosomes/sister chromatids to properly segregate

Question 6

monosomy

Answer 6

loss of one member of homologous pair

Question 7

trisomy

Answer 7

one additional member to homologous pair

Question 8

non-disjunction in Meiosis I

Answer 8

all 4 gametes are abnormal
zygotes= 2n-1 and 2n+1

Question 9

non-disjunction in meiosis II

Answer 9

2 normal gametes, and 2 abnormal
zygotes= 2n, 2n-1, 2n+1

Question 10

Non-disjunction of autosomes

Answer 10

affects on large chromosomes= short lifespans
affects on small chromosomes= full lifespans

Question 11

Mammalian Sex Chromosome

Answer 11

X and Y as pairing partners that normally segregate
imbalance in sex chromosome is less damaging than imbalance in autosomes

Question 12

homogametic

Answer 12

XX
female

Question 13

heterogametic

Answer 13

XY
males

Question 14

SRY gene

Answer 14

sex-determining region on Y chromosome

Question 15

Random X inactivation

Answer 15

only 1 X is in an active state
other Xs are inactive and condensed into Barr Bodies

Question 16

Barr bodies

Answer 16

small darkly staining body in interphase cells of normal females

Question 17

Changing copy number of a gene can cause…

Answer 17

unbalanced gene dosage

Question 18

deletion

Answer 18

impact depends on what was deleted

Question 19

duplication

Answer 19

human segmental duplications make up 4% of human genome
gives opportunity for evolution of new proteins

Question 20

inversions

Answer 20

order of alleles changes, may lead to alteration in gene function/regulation

Question 21

paracentric inversion

Answer 21

does NOT include centromere

Question 22

pericentric inversion

Answer 22

includes the centromere

Question 23

Translocations

Answer 23

movement of genetic material between nonhomologous chromosomes
two types:
- reciprocal translocations
- robertsonian translocations

Question 24

reciprocal translocation

Answer 24

part of one chromosome exchanges with part of another chromosome

Question 25

Robertsonian translocation

Answer 25

occurs between short arm of acrocentric chromosome and the long arm of another
leads to chromosome getting lost

Question 26

Translocations can _____ chromosome number

Answer 26

lower

Question 27

Uniparental Disomy

Answer 27

attempt to correct aneuploidy
both homologs passed from one parent

Question 28

Why is it a problem to have both homologs passed from one parent?

Answer 28

• will be homozygous for any detrimental allele
• imprinting: only one parental allele is expressed in some cells while the other is repressed