Ch. 8

Question 1

Aneuploids

Answer 1

alters the number of chromosomes

Question 2

chromosome rearrangements (provide the types)

Answer 2

alter the chromosome structure; duplication, deletion, inversion, translocation

Question 3

Polyploids

Answer 3

one or more additional sets of chromosomes (some plants, tumors)

Question 4

non-disjunction

Answer 4

failure of homologous chromosomes or sister chromatids to segregate properly

Question 5

Correct gene dosage means…

Answer 5

the proper number and kind of chromosomes are required for proper development

Question 6

Monosomy

Answer 6

loss of one member of the homologous pair; almost always lethal

Question 7

Trisomy

Answer 7

one additional member of an homologous pair; almost always lethal

Question 8

When there is nondisjunction in meiosis I, how many gametes are abnormal

Answer 8

4

Question 9

Nondisjunction in meiosis II

Answer 9

2 normal gametes, 2 abnormal gametes

Question 10

nondisjunction occurs in

Answer 10

anaphase- problem in separation

Question 11

Trisomy 13

Answer 11

Patau Syndrome; extreme malformation of organ systems

Question 12

trisomy 18

Answer 12

Edward syndrome; slow growth and multiple abnormalities

Question 13

Trisomy 21

Answer 13

Down syndrome; characteristic facial features and wide range of cognitive impairment

Question 14

Which is more damaging- imbalance in sex chromosomes or imbalance in autosomes?

Answer 14

imbalance in autosomes

Question 15

Random X-inactivation

Answer 15

only 1 X is in an active state; all others are inactive and condensed into Barr bodies

Question 16

Barr Body

Answer 16

small, darkly staining body in interphase cells of normal female

Question 17

Klinefelter syndrome

Answer 17

XXY; poor beard growth, breast development, and under-developed testes

Question 18

Turner Syndrome

Answer 18

X0; characteristic facial features, web of skin, constriction of aorta, poor breast development, under-developed ovaries

Question 19

changing the copy number of a gene can result in…

Answer 19

unbalanced gene dosage

Question 20

duplication

Answer 20

a mutation in which part of the chromosome has been doubled

Question 21

human segmental duplications make up how much of the human genome

Answer 21

about 4%

Question 22

Deletion

Answer 22

the loss of a chromosome segment (the impact of a deleted region depends on what was deleted)

Question 23

If the centromere is deleted

Answer 23

no segregation during mitosis or meiosis; gets lost

Question 24

Inversions

Answer 24

The order of alleles change (a chromosome segment is inverted)

Question 25

paracentric inversion

Answer 25

does not include the centromere

Question 26

Pericentric inversion

Answer 26

includes the centromere

Question 27

translocations

Answer 27

movement of genetic material between NON-homologous chromosomes or the same chromosome

Question 28

reciprocal translocations

Answer 28

reciprocal exchange of segments between 2 non-homologous chromosomes

Question 29

What are 2 examples of a reciprocal translocation?

Answer 29

Burkitt’s Lymphoma and Philadelphia chromosome

Question 30

Robertsonian Translocation

Answer 30

occurs between the short arm of an acrocentric chromosome and the long arm of another; generates a metacentric chromosome with 2 long arms and another chromosome with 2 very short arms

Question 31

Uniparental Disomy

Answer 31

both homologs from one parent

Question 32

What are examples of uniparental disomy

Answer 32

Angelman Syndrome and Prader-Willi Syndrome

Question 33

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

Answer 33

homozygosity for any detrimental alleles; imprinting

Question 34

solving nondisjunction problems:
if we have one X^something at the end it is from

Answer 34

the opposite parent
so X^aY crossed with X^- X^-
which gives X^a which would be nondis in mother but we can’t determine meiosis 1 or 2

Question 35

in a nondisjunction problem what if we have both alleles from that parents at the end

Answer 35

there was nondisjunction in that parent
if it has both of their alleles= meiosis 1
if it has one of their alleles replicated= meiosis 2