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

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

Why do we use pedigrees?

A

Geneticists often use pedigrees to study the inheritance of characteristics in humans

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

How could you distinguish between an autosomal recessive trait with higher penetrance in males and an X-linked recessive trait?

A

X-linked recessive traits are only passed to sons from mothers, not from fathers

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

How do linked genes behave during meiosis?

A

Linked genes travel together in meiosis, eventually arriving at the same destination ( same gamete), and are not expected to assort independently

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

How does crossing over affects recombination?

A

Crossing over takes place in meiosis and leads to recombination

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

What are the three models of DNA replication?

A

Conservative, Semi-conservative and dispersive

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

What are the three main things needed for DNA replication?

A

Parental DNA, enzymes, and nucleotide triphosphate

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

What are the stages of DNA replication?

A

Initiation, elongation and termination

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

The Central Dogma: How does information flow?

A

DNA to mRNA to protein

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

What does it mean to say the code is “degenerate”?

A

some amino acids are specified by more than one codon

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

What is the addition of a long chain of adenine residues to the 3’ end of the transcript called?

A

3’ poly-A tail

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

The complete set of chromosomes possessed by an organism is called a

A

Karyotype

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

Which type of chromosome mutation results in a chromosome segment that is turned 180 degrees?

A

Inversion

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

The centromere is at or very near the end in which type of chromosome?

A

Acrocentric

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

Which type of chromosome mutation INCREASES the amount of genetic material?

A

Duplication

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

What are the four basic types of chromosome rearrangements

A

deletion, inversion, duplication and translocation

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

which of the following is NOT a rearrangement that causes chromosomal mutations?

A

transformation

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

The centromere is located approximately in the middle of which type of chromosome?

A

Metacentric

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

Which type of chromosome mutation DECREASES the amount of genetic material?

A

deletion

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

If a deletion occurs in a gene that encodes DNA polymerase I and no functional DNA polymerase I is produced, what will be the MOST likely consequence of this mutation?

A

The DNA strands would contain pieces of RNA

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

True or False: Some DNA polymerases have the ability to function in DNA repair mechanisms

A

True

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

Which of the following enzyme and function pairs is incorrectly matched

A

DNA helicase; rewinding and reforming the DNA double helix as the replication terminates

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

What type of synthesis occurs on the leading strand?

A

Continuous

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

Okazaki fragments are found in all the following EXCEPT in

A

The leading strand

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

What is the function of DNA ligase?

A

Connects Okazaki fragments by sealing nicks in the sugar-phosphate backbone

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

Which of the following typically only have in origin of replication?

A

prokaryotes

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

Which activity is NOT associated with DNA polymerases?

A

Ability to synthesize a DNA from scratch without a primer

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

Meselson and Stahl showed that DNA is replicated by a

A

semiconservative system

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

______ are tandemly repeated DNA sequences located at the ends of eukaryotic chromosomes

A

Telomeres

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

What is a proband?

A

a person serving as the starting point for the genetic study of a family

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

One disease that arise from a Robertsonian translocation between two chromosomes

A

Down syndrome between chromosome 21 and 14

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

What is the start codon in Eukaryotes?

A

AUG

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

Gametes with new combinations of alleles are called

A

recombinant gametes

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

The arrangement, in which wild-type alleles are found on one chromosome and mutant alleles are found on the other chromosome is known as

A

coupling or cis configuration

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

The arrangement, in which each chromosome contains one wild type and one mutant allele is called

A

repulsion or trans configuration

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

What conditions can geneticist often use pedigrees to study inheritance and characteristics of humans?

A
  • autosomal dominant traits
  • autosomal recessive traits
  • X-linked recessive traits
  • X-linked dominant traits
  • Y-linked traits
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

True or False: autosomal dominant traits appear equally in males and females?

A

True, affected people have at least one affected parent

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

True or False: autosomal recessive traits tend to skip generations

A

True, traits more likely to appear among progeny of related parents

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

True or False: An affected male does not pass the trait to his sons in an X-linked recessive trait?

A

True, but an affected male can pass the allele to his daughter who will be unaffected

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

Pedigree characteristics Y-linked traits?

A
  • only males are affected
  • passed from father to all sons
  • does not skip generations
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Autosomal recessive traits often appear in pedigrees in which there have been consanguine mating because …

A

these traits appear only when both parents carry a copy of the gene for the trait, which is more likely when the parents are related

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

What is a concordant trait?

A

A trait shared by both members of a twin pair

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

What are the two types of twins?

A
  • monozygotic and dizygotic
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

A trait exhibits 100% concordance in both monozygotic and dizygotic twins. What conclusion can you draw about the role of genetic factors in determining differences in the trait

A

both genetic and environment factors are important

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

Reasons for seeking genetic counseling

A
  • a person knows of a genetic disease in the family
  • An older woman becomes pregnant or wants to become pregnant
  • A couple experiences difficulties achieving a successful pregnancy
  • a known genetic disease in the family
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What is a pedigree?

A

a pictorial representation of a family history, essentially a family tree that outlines the inheritance of one or more characteristics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

In a pedigree a male is pictured as..

A

square

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

In a pedigree a female is pictured as…

A

circle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

In a pedigree a unknown sex is pictured as…

A

diamond

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

In a pedigree an unaffected person is pictured as..

A

uncolored

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

In a pedigree an affected person is pictured as..

A

colored in

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

In a pedigree a carrier of the gene but does not have the trait is pictured as…

A

a colored circle in the middle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

In a pedigree an asymptomatic carrier is pictured as…

A

having a line go through it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

In a pedigree a deceased person is pictured as…

A

a line going across it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

Waaredenburg syndrome

A

-inherited as an autosomal dominant trait
- characterized by deafness, fair skin, visual problems and a white forlock

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

True or False; autosomal dominant traits tend to skip generations

A

False, they do not skip generations because they only require the inheritance of one dominant allele to express the phenotype

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

What is an example of an X-linked recessive trait?

A

Hemophilia

56
Q

Autosomal recessive traits often appear in pedigrees in which there have been consanguine mating because these traits…

A

Appear only when both parents carry a copy of the gene for the trait

57
Q

Autosomal recessive traits

A
  • usually appear in both sexes with equal frequency
  • tends to skip generations
  • affected offspring are usually born to unaffected parents
  • When both parents are heterozygous, approximately 1/4 of the offspring will be affected
  • appears among the children of consanguineous marriages
58
Q

Autosomal dominant trait

A
  • usually appears in both sexes with equal frequency
  • both sexes transmit the trait to their offspring
  • Does not skip generations
  • affected offspring must have an affected parent unless they possess a new mutation
  • when one parent is affected (heterozygous) and the other parent is unaffected, about half the offspring will be affected
  • unaffected parents do not transmit the trait
59
Q

X-linked recessive trait

A

-Usually more males than females are affected
- affected sons are usually born to unaffected mothers; thus, the trait skips generations
- About half of a carrier (heterozygous) mother’s sons are affected
- Never passed from father to son
- All daughters of affected fathers are carriers

60
Q

X-linked dominant trait

A
  • both females and males are affected; more females than males are affected
  • does not skip generations
  • affected sons must have an affected mother; affected daughters must have an affected mother or father
  • affected fathers pass the trait to all their daughters
  • affected mothers (if heterozygous) pass the trait to half of their sons and half of their daughters
61
Q

Y- Linked traits

A
  • only males are affected
  • passed from father to all sons
  • does not skip generations
62
Q

How could you distinguish between an autosomal recessive trait with a higher penetrance in males and an X-linked recessive trait?

A

X-linked recessive traits are only passed to sons from mothers, but not from fathers

63
Q

Dizygotic twins

A
  • two separate eggs are fertilized by two different sperm
  • produce genetically distinct zygote
  • influenced by heredity and genetic factors
64
Q

monozygotic twins

A
  • A single egg is fertilized by a single sperm
  • Splits in early development into two separate embryos
  • genetically identical
  • 100% genes in common
65
Q

Discordant trait

A

Only one member of the twin pair has the trait

66
Q

Concordance

A

the percentage of twin pairs that are concordant for a trait

67
Q

Genetic counseling

A

Provides info related to hereditary conditions

68
Q

Asthma caused by genetics&environment : Twin test

A
  • Monozygotic: 65%
  • Dizygotic: 37%
69
Q

Complications in interpreting genetic test

A
  • some diseases caused by multiple mutations
  • incomplete penetrance
  • environmental factors
70
Q

What is GINA?

A

Genetic information nondiscrimination act

71
Q

True or False: Pattern baldness is a hereditary trait

A

True

72
Q

Genes located close together on the same chromosome are called…

A

linked genes

73
Q

Linked genes

A
  • travel together in meiosis, eventually arriving at the same destination (same gamete)
  • Are not expressed to assort independently
74
Q

nonrecombinant gametes

A

Gametes that contain only original combinations of alleles that were present in the parents

75
Q

DNA recombination

A

the exchange of genetic material either between multiple chromosomes or between different regions of the same chromosome

76
Q

Recombination

A

The sorting of alleles into new combinations

77
Q

Recombination frequency calculation

A

Number of recombinant progeny
___________________________________ X 100%
Total number of progeny

78
Q

True or False: crossing over takes place in prophase I of meiosis

A

True

79
Q

True or False: A two-strand double crossover between two linked genes does not produce nonrecombinant gametes

A

False, a two-strand double crossover between two linked genes produces ONLY nonrecombinant gametes

80
Q

Middle Locus Rules

A
  1. write all possible progeny
  2. determine&highlight the double crossover progeny
  3. Place Loci in order so each has a chance to be in the middle
  4. Flip the middle locus
  5. which outcome matches the double progeny is the middle locus
81
Q

A three-point test cross is carried out btw three-linked genes. The resulting nonrecombinant progeny are s+r+c+ and src, the double crossover progeny are src+ and s+r+c. What is the middle locus

A

It’s C: but girl u need to show work

82
Q

What is RFLPs

A

Restriction fragment length polymorphism

83
Q

What is it when the centromere is at or very near the end of the chromosome?

A

telocentric

84
Q

Submetacentric

A

the centromere is displaced toward one end, creating a long arm and a short arm

85
Q

Aneuploidy

A

alters the number of chromosomes

86
Q

Polyploidy

A

One or more complete sets of chromosomes are added

87
Q

Chromosome duplication

A

a segment of the chromosome is duplicated

88
Q

Chromosome deletion

A

A segment of the chromosome is deleted

89
Q

Chromosome inversion

A

A segment of the chromosome is turned 180

90
Q

Chromosome translocation

A

A segment of a chromosome moves from one chromosome to a non-homologous chromosome or to another place on the same chromosome

91
Q

pseudodominance

A

indication that one of the homologous chromosomes has a deletion

92
Q

haploinsufficient

A

when a single copy of a gene is not sufficient to produce a wild-type phenotype

93
Q

Paracentric inversions

A

Inversions that do not include the centromere, such as AB.CFEDG
(Para meaning “next to”)

94
Q

Pericentric inversions

A

inversions that include the centromere, such as ADC.BEFG
(Peri meaning “around)

95
Q

nonreciprocal translocation

A

genetic material moves from one chromosome to another without any reciprocal exchange

96
Q

robertsonian translocation

A

the long arms of two acrocentric chromosomes become joined to a common centromere through translocation, generating a metacentric chromosome with two long arms and another chromosome with two very short arms

97
Q

Causes of aneuploidy

A
  • deletion of centromere during mitosis and meiosis
  • nondisjunction during meiosis and mitosis`
98
Q

Nullisomy

A

type of aneuploidy
- the loss of both members of a homologous pair of chromosomes
- represented as 2n-2
- nullisomic zygote has 44 chromosomes

99
Q

Monosomy

A

type of aneuploidy
- the loss of a single chromosome
- represented as 2n-1
- monosomic zygote has 45 chromosomes

100
Q

Trisomy

A

type of aneuploidy
- the gain of a single chromosome
- represented as 2n+1
- trisomic zygote has 47 chromosomes

101
Q

Tetrasomy

A

type of aneuploidy
- the gain of two homologous chromosomes
- represented as 2n+2
- tetrasomic zygote has 47 chromosomes

102
Q

Trisomy 21

A
  • down syndrome
  • 75% random nondisjunction in egg formation
  • the translocation of part of chromosome 21 to another chromosome results in familial down syndrome
103
Q

Nondisjunction

A

failure of normal chromosome separation during nuclear division leading to abnormal chromosomes in daughter cells

104
Q

Trisomy 18

A
  • Autosomal Aneuploid
  • Edward Syndrome
  • 1/8,000 births
105
Q

Trisomy 13

A
  • Autosomal Aneuploid
  • Patau Syndrome
  • 1/ 15,000 births
106
Q

Trisomy 8

A
  • Autosomal Aneuploid
  • 1/ 25,000 - 1/50,000 births
107
Q

True or False: the frequency of aneuploidy increases with maternal age

A

True, most cases of down syndrome and other types of aneuploidy in humans arise from maternal nondisjunction

108
Q

Autopolyploidy

A

Caused by accidents of mitosis or meiosis that produce extra set of chromosomes, all derived from a SINGLE species

109
Q

Allopolyploidy

A

arises from hybridization between two species; the resulting polyploid carries chromosome sets derived from two or more species

110
Q

Significance of polyploidy

A
  • increase in cell size
  • larger plant attributes
  • evolution: many gives rise to new species
111
Q

Species A has 2n=16 and species B has 2n=14. How many chromosomes would be found in an allotriploid of these two species

A

2n= 16 2n=14
2n/2= 16/2 2n/2= 14/2
n= 8 n= 7
1n= 8 1n=7
SWITCH
8+14= 22 7+18= 23
ANSWER: 22 or 23

112
Q

DNA Replication

A
  • the process by which the genetic material is copied
  • The orginal DNA strands are used as templates for the synthesis of new strands
  • occurs quickly and accurately and the appropriate time in the life of the cell
113
Q

True or False: Genetic information must be accurately copied every time a cell divides

A

True, replication HAS TO BE extremely accurate
- one error = million base pairs would result in 6,400 mistakes every time a cell divides! This would be catastrophic!

114
Q

Conservative Replication

A
  • Both strands of parental duplex remain intact
  • new DNA copies consist of all new molecules
115
Q

Semiconservative replication

A

Daughter strands each consist of one parental strand and one new strand

116
Q

Dispersive replication

A

New DNA is dispersed throughout each strand of both daughter molecules and replication

117
Q

Where does Translation occur?

A

Cytoplasm

118
Q

Where does transcription occur?

A

Nucleus

119
Q

What is RNA polymerase?

A

Enzyme that unzips double stranded DNA and synthesizes the formation of mRNA

120
Q

What is a codon?

A

3 base sequence of mRNA that codes for a specific amino acid

121
Q

What is an anticodon?

A

Set of three ribonucleotides complementary to a specific mRNA codon sequence

122
Q

Can more then one ribosome translate an mRNA strand at once?

A

A single mRNA can be translated simultaneously by multiple ribosomes

123
Q

How did Meselson and Stahl distinguish between old and new DNA

A

Used two isotopes of nitrogen, 14N and 15N

124
Q

Conclusion of the Meselson and Stahl experiment?

A

DNA replication in E.Coli is semiconservative

125
Q

How many bands of DNA would be expected in Meselson and Stahl’s experiment after two rounds of conservative replication?

A

Two Bands

126
Q

The newly synthesized DNA strand is _______ and ________ to the template strand

A

antiparallel and complementary

127
Q

Lagging Strand

A

Newly made strand that undergoes discontinuous replication

128
Q

Primers are synthesized where on the lagging strand?

A

At the beginning of every Okazaki fragment

129
Q

Which bacterial enzyme removes the primers?

A

DNA polymerase I

130
Q

What is the direction of transcription?

A

5’ to 3’

131
Q

What is a holoenzyme?

A

Core enzyme & sigma factor

132
Q

Upstream?

A

left side of promoter

133
Q

Downstream?

A

Right side of promoter

134
Q

True or false: transcription occurs constantly?

A

False, there will be pauses because of features of the DNA and RNA

135
Q

Does transcription stop at a “stop” codon?

A

No

136
Q

Eukaryotic Transcription

A
  • 3 different RNA polymerases instead of 1
  • nucleosome structure
  • promoters
137
Q

What is a mutagen?

A

Any agent that increases the number of mutations above background level radiation chemicals

138
Q
A

Genetics (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions