Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Genetics > Exam 2 > Flashcards

Exam 2 Flashcards

1
Q

when does crossing over occur

A

prophase 1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what happens in meiosis 2 with normally-linked genes

A

they assort independently and end up in different gametes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what happens if there is no crossing over in meiosis 1

A

there will be no recombinant gametes…they will all be parental

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

single crossover

A

50% parental, 50% recombinant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

recombination frequency equation

A

number of recombinant progeny/all progeny x 100

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

% recombination white eyes yellow bodies

A

1.5%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

% recombination yellow bodies cut wings

A

17.7%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

% recombination yellow bodies vermillion eyes

A

34.5%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is a test cross

A

crossing an F1 with a homozygous recessive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

is there recombination in male drosophila

A

no

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

why do male drosophila not have recombination

A

they don’t form synaptonemal complexes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is responsible for breakage of chromosomes during crossing over

A

something-ase. protease?

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

can sister chromatids have crossover

A

they can but wouldn’t do anything?

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

double crossover - 2 strands

A

2 crossovers occurring, all parental chromosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

triple crossover

A

three crossovers occurring on the four strands

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

quadruple crossover

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

double crossover - 3 strands

A

half parental, half recombinant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

double crossover - 4 strands

A

all recombinant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

% recombination white eyes mini wings

A

31.5%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

% recombination yellow body rudimentary wings

A

50%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

explain theoretical vs empirical map distances

A

theoretical map distance for percent recombination is always higher than empirical

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

over what distance is percent recombination a good estimate

A

short distances: less than 25 MU

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

over what distance is percent recombination a bad estimate

A

long distances: over 35 MU

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

are far apart genes likely to be linked?

A

no

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

how can you find the number of recombinant offspring in a cross

A

divide recombinant by 2 and excess by two and multiply proportion by whole number of progeny to get estimate.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

calculating recombinant percent from first gene to middle gene

A

R1 + R1 + D + D / total # x 100

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

calculating recombinant percent from middle gene to end gene

A

R2 + R2 + D + D / total # x 100

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

do you do count doubles twice when calculating recombination frequency

A

yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

calculating coefficient of coincidence

A

number of doubles obs / number of doubles exp

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

calculating interference

A

1-coefficient of coincidence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

probability of a crossover in region 1

A

.122

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

probability of a crossover in region 2

A

.146

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

probability of a double crossover

A

.018

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

how do you calculate the number of expected doubles

A

you multiply .018 by the total number of progeny

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

what if interference is 1

A

no doubles occured

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

what if interference is negative

A

more occurred than expected

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

are genetic maps linear

A

yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

are map distances additive

A

yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

characteristics of 3 unlinked genes

A

all phenotypic classes will be equal in frequency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

characteristics of 2 linked, 1 unlinked genes

A

parentals=doubles, 2 sets of recombinants = but less than parentals and doubles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

characteristics of 3 linked genes

A

four distinct sets of phenotypic classes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

G and Q banding

A

fluoresces karyotypes to show chromosome bands

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

what are the 4 chromosome aberrations

A

deletions, duplications, inversions, translocations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

what is a chromosome deletion

A

a portion of the chromosome is deleted. usually recessive lethal. can show a dominant effect.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

what is a chromosome duplication

A

a portion of the chromosome is duplicated.

46
Q

what is a chromosome inversion

A

a portion of the chromosome is flipped 180 degrees

47
Q

what is a chromosome translocation

A

a portion of the chromosome moves to a non-homologous chromosome or another place on the same chromosome

48
Q

pseudodominance

A

when a single recessive allele is inherited but still expressed

49
Q

when does the deletion loop form on chromosome deletions

A

during prophase 1

50
Q

what are polytene chromosomes

A

they remain condensed during interphase. homologous chromosomes remain paired even though there is no meiosis. they are large and easy to see.

51
Q

genetic vs cytological maps

A

co-linear but not co-metric

52
Q

cri-du-chat syndrome

A

cat-like cry, intellectually challenged, small head, small jaw, wide-set eyes

53
Q

deletions are consistently found where

A

in patients with solid tumors

54
Q

duplications in wild-type chromosomes

A

chromosomes don’t align properly, so unequal crossing over

55
Q

pericentric inversion

A

includes the centromere

56
Q

paracentric inversion

A

does not include the centromere

57
Q

inversion characteristics

A

no gene imbalance, can have position effects, if moved next to heterochromatin position effects can be patchy

58
Q

dna + proteins

A

chromatin

59
Q

euchromatin

A

stains normally, thought to contain genes, loosely packed

60
Q

heterochromatin

A

densely staining, condensed chromatin thought to be genetically inert. mostly repetitive dna, tightly packed

61
Q

constitutive

A

always on

62
Q

facultative

A

occurring sometimes

63
Q

result of a crossover inside a paracentric inversion

A

gametes containing chromatin involved in crossover are non-viable. gametes containing chromatin not involved in crossover are viable.

64
Q

result of a crossover inside a pericentric inversion

A

gametes containing chromatin involved in crossover are non-viable. gametes containing chromatin not involved in crossover are viable.

65
Q

coadapted gene complex

A

a group of genetic traits with high fitness when they occur together, but without each other have low fitness

66
Q

reciprocal translocation

A

no predictable phenotypes, pairing of homozygotes is normal, pairing of heterozygotes will result in a cross shape

67
Q

how chromosomes separate in anaphase 1 - alternate segregation

A

viable gametes

68
Q

how chromosomes separate in anaphase 1 - adjacent 1 segregation

A

non-viable gametes

69
Q

how chromosomes separate in anaphase 1 - adjacent 2 segregation (rare)

A

non-viable gametes

70
Q

5:11 translocation

A

Cr- du Chat

71
Q

8:14 reciprocal translocation

A

Burkitt’s lymphoma

72
Q

Reciprocal Translocations in Oenothera

A

ring chromosomes

73
Q

polyploid

A

any organism with more than 2 sets of chromosomes

74
Q

autopolyploids

A

have multiple of the species’ original sets of chromosomes

75
Q

allopolyploids

A

contain sets of chromosomes from different species

76
Q

pairing possibilities in tetraploids

A

two bivalents, one quadrivalent, univalent + trivalent

77
Q

in allopolyploids who is viable

A

F1 will make non-viable progeny

78
Q

why are hybrids sterile

A

meiosis is highly unstable

79
Q

Karpechenko’s Experiments

A

there can be a few fertile offspring of hybrids

80
Q

XO

A

Turner’s Syndrome

81
Q

XXX

A

Trisomic X

82
Q

XXXX

A

Tetrasomic X

83
Q

XXXXX

A

Pentasomic X

84
Q

XYY

A

Jacob’s Syndrome

85
Q

XXY

A

Kleinfelter’s Syndome

86
Q

XXYY

A

Kleinfelter’s Syndome double trisomic

87
Q

XXXY

A

Kleinfelter’s Syndome tetrasomic

88
Q

2N

A

normal

89
Q

2N-1

A

monosomic

90
Q

2N-1-1

A

double monosomic

91
Q

2N-2

A

nullosomic

92
Q

2N+1

A

trisomic

93
Q

2N+1+1

A

double trisomic

94
Q

2N+2

A

tetrasomic

95
Q

Barr Body

A

condensed, inactivated X chromosome

96
Q

Barr Bodies in X0

A

0

97
Q

Barr Bodies in XX

A

1

98
Q

Barr Bodies in XXX

A

2

99
Q

Barr Bodies in XXXX

A

3

100
Q

Barr Bodies in XXXXX

A

4

101
Q

Barr Bodies in XY

A

0

102
Q

Barr Bodies in XYY

A

0

103
Q

Barr Bodies in XXY

A

1

104
Q

Barr Bodies in XXYY

A

1

105
Q

Barr Bodies in XXXY

A

2

106
Q

Barr Bodies in XXXXY

A

3

107
Q

mechanism of x-chromosome inactivation

A

repressor of inactivation binds to one x chromosome

108
Q

Down Syndrome

A

trisomic 21

109
Q

Edward Syndrome

A

trisomic 18

110
Q

Patau Syndrome

A

trisomic 13

111
Q

Warkany Syndrome

A

trisomic 8

Genetics (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions