Brainscape's Knowledge GenomeTM

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


See full index

BIOL 1105 > 17: Inheritance of Genetic Information II > Flashcards

17: Inheritance of Genetic Information II Flashcards

Module 3, Lesson 6

1
Q

The chromosomal theory of inheritance was first proposed by…

A

Walter Sutton

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

The chromosomal theory of inheritance states that…

A

Chromosomes are the carriers of genetic information and the basis for genetic inheritance.

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

The first evidence that genes resided on chromosomes was provided by…

A

T.H. Morgan

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

In Morgan’s F1 generation, all the fruit flies had…

A

Red eyes

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

What was unusual about Morgan’s F2 generation?

A

Only male fruit flies had white eyes

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

How is sex determined in fruit flies?

A

The number of X chromosomes

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

During meiosis, females can produce…

A

X gametes only

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

During meiosis, males can produce…

A

Either X or Y gametes

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

The sex of a zygote is determine by the…

A

Father

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

In humans, sex is determined by…

A

The presence or absence of the Y chromosome

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

True or false:

The human Y chromosome is very similar to the X chromsome.

A

False

The Y chromosome is highly condensed and has few expressed genes.

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

The “default” sex for humans is…

A

Female

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

In order for a zygote to develop as male…

A

The SRY gene (on the Y chromsome) must be present

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

Humans have ____ pair(s) of sex chromsomes.

A

1

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

Chromosome pairs that do not influence the individual’s sex are called…

A

Autosomes

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

Humans have ____ pair(s) of autosomes.

A

22

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

The human genome contains a total of ____ chromosome pairs.

A

23

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

A trait controlled by a gene located on the X chromosome is considered…

A

Sex-linked or X-linked

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

True or false:

A male who expresses an abnormal X-linked trait can pass that trait onto his sons.

A

False

He will pass the trait onto his daughters, but cannot pass it on to his sons.

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

For X-linked traits, the male phenotype is dependent on the X chromosome inherited from his…

A

Mother

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

Females will only express an X-linked recessive trait if…

A

They are homozygous for that trait

(actually this isn’t entirely true but not relevant to a basic biology course)

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

True or false:

The daughters of a male who is affected by an X-linked trait and a female who is a carrier for the trait may be affected.

A

True

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

True or false:

All X-linked traits are recessive.

A

False

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

Regulators of gene expression that do not change the DNA sequence are called…

A

Epigenetic mechanisms

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

List two examples of epigenetic mechanisms.

A
  1. Dosage compensation
  2. Genomic imprinting
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

____ ensures that an equal number of genes are expressed from sex chromosomes.

A

Dosage compensation

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

True or false:

Because human females have twice as many X-linked genes as males, they have twice as much gene expression for these traits.

A

False

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

How does dosage compensation occur in humans?

A

In females, one X chromosome is inactivated and condenses into a Barr body

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

True or false:

The X chromosome that is inactivated varies randomly from cell to cell.

A

True

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

Females that are heterozygous for an X-linked trait are sometimes called…

A

“Genetic mosaics”

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

The unique coloration of calico cats is due to…

A

X-chromosome inactivation

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

In which two groups of organisms does genomic imprinting occur?

A
  1. Flowering plants
  2. Mammals (incl. humans)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Genes that are “imprinted” are…

A

Inactivated

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

Cells determine which genes to imprint based on…

A

Which parent they were inherited from

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

____ occurs when one allele is inactivated while the other is expressed.

A

Genomic imprinting

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

True or false:

Traits associated with organelle genomes (mitochondria and chloroplasts) follow Mendelian inheritance patterns.

A

False

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

The organelle genome is usually inherited solely from the…

A

Mother

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

Organelle genes are passed from parent to offspring via…

A

Maternal inheritance

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

The first human disease shown to result from a mutation in a protein was…

A

Sickle-cell anemia

40
Q

What causes sickle-cell anemia?

A

A single base substitution in the gene that codes for hemoglobin

41
Q

A person who is homozygous for sickle-cell anemia will…

A

Exhibit intermittent illness and have a reduced lifespan

42
Q

An individual who is heterozygous for sickle-cell anemia will…

A

Appear normal under normal oxygen conditions

43
Q

Sickle-cell anemia is particularly prevalent in people of ____ descent.

A

African

44
Q

Why is the proportion of people heterozygous for sickle-cell anemia abnormally high in African populations?

A

Having one mutated copy of the gene confers higher resistance to malaria

45
Q

The failure of homologues or sister chromatids to separate properly during meiosis is called…

A

Nondisjunction

46
Q

____ is the gain or loss of a chromosome.

A

Aneuploidy

47
Q

____ refers to the loss of a chromosome.

A

Monosomy

(because there is now only one chromsome from that pair present in the cell)

48
Q

____ refers to the gain of a chromosome.

A

Trisomy

(because there are now three chromosomes from that pair in the cell

49
Q

In humans, individuals with trisomy can only survive if the trisomy occurs on one of ____ autosome pairs.

A

Five

50
Q

Infants born with trisomy 13, 15, or 18…

A

Die within a few months of birth

51
Q

People born with trisomy 21 or 22…

A

Can survive to adulthood, albeit with physical and mental disabilities

52
Q

“Trisomy 21” is more commonly known as…

A

Down Syndrome

53
Q

Down Syndrome can also occur if a small, critical portion of chromosome 21 is…

A

Translocated

54
Q

The consequences of nondisjunction in sex chromosomes is generally ____ severe than in autosomes.

A

Less

55
Q

Nondisjunction of sex chromosomes often results in…

A

Abnormal features, mental disabilities, and sterility

56
Q

True or false:

Some individuals with sex chromosome nondisjunction can still be fertile.

A

True

57
Q

The fertilization of an XX egg with an X sperm results in…

A

Triple X syndrome

58
Q

A zygote with Triple X syndrome will…

A

Develop female, just with two Barr bodies

59
Q

The fertilization of an XX egg with a Y sperm results in…

A

Klinefelter syndrome

60
Q

A zygote with Klinefelter syndrome will…

A

Develop male, with female characteristics and mental disability

61
Q

The fertilization of an O egg with an X sperm results in…

(an O egg is one that has no sex chromosome)

A

Turner syndrome

62
Q

A zygote with Turner syndrome will…

A

Develop into a sterile female with immature sex organs and diminished mental abilities

63
Q

A zygote fertilized by an O egg and a Y sperm is…

A

Nonviable

64
Q

The fertilization of an X egg with a YY sperm results in…

A

Jacobs syndrome

65
Q

A zygote with Jacobs syndrome will…

A

Develop into a fertile male with larger stature and some mental disability

66
Q

True or false:

Many genetic disorders can be predicted and detected in utero.

A

True

67
Q

____ provides risk assessment and guidance to parents about how genetic conditions may affect phenotype.

A

Genetic counseling

68
Q

A mutation in the BRCA1 or BRCA2 results in…

A

A greatly elevated risk of breast cancer in women

69
Q

Genetic counselors can predict the likelihood of genetic disorders using…

A

A pedigree analysis of the parents

70
Q

List two methods of collecting fetal cells for genetic testing.

A
  1. Amniocentesis
  2. Chorionic villi sampling
71
Q

During ____, fetal cells are collected from the amniotic cavity.

A

Amniocentesis

72
Q

During ____, fetal cells are collected from the fetal portion of the placenta.

A

Chorionic villi sampling

73
Q

Both amniocentesis and chorionic villi sampling carry a risk of…

A

Miscarriage

74
Q

____ is the independent assortment of genes on the same chromosome as a result of crossing over.

A

Genetic recombination

75
Q

When crossing over occurs, parental alleles are…

A

Recombined

76
Q

Crossing over occurs during ____ of meiosis.

A

Prophase 1

77
Q

Recombination allows us to measure…

A

The distance between genes on a chromosome

78
Q

T.H. Morgan suggested that the frequency of recombinant offspring reflected…

A

The location of relevant genes on the chromosome

79
Q

As physical distance increases, the probably of recombination…

A

Increases

80
Q

We use ____ to measure recombinant frequency.

A

Test crosses

81
Q

If a significant number of offspring display a recombinant phenotype, then…

A

The genes must be far apart

82
Q

If few offspring display the recombinant phenotype, then…

A

The genes must be close together

83
Q

Two genes that are close together are called…

A

“Linked traits”

84
Q

A test cross that examines two gene loci is called a…

A

Two-point cross

85
Q

During a two-point cross…

A

Doubly heterozygous offspring are crossed with the homozygous recessive parent.

86
Q

Offspring with ____ are not recombinant.

A

Parental phenotypes

87
Q

Offspring with a mixture of parental traits are…

A

Recombinant

88
Q

Dividing the number of recombinant offspring by the total number of offspring yields the…

A

Recombination frequency

89
Q

Each 1% of the recombination frequency represents a unit of measure called the…

A

Map unit or centimorgan

90
Q

List four methods that can be used to map the human genome.

A
  1. Test crosses and linkage analysis
  2. Disruption of genes of unknown functions
  3. Inducing mutant phenotypes
  4. Analysis of historical pedigrees
91
Q

Why was it originally difficult to map the human genome?

A

There were limited useful genetic markers and limited historical data

92
Q

Human genome mapping was made significantly easier with the discovery of…

A

Large numbers of genetic markers that do not alter phenotype

93
Q

What are the two “landmarks” that aid in mapping the human genome?

A
  1. Short Tandem Repeats (STRs)
  2. Single Nucleotide Polymorphisms (SNPs)
94
Q

____ are a sequence of 2-4 repeated bases that differ in number between individuals.

A

Short tandem repeats
(STRs)

95
Q

____ are differences that affect a single base of a gene locus, with a low frequency in the general population.

A

Single nucleotide polymorphisms
(SNPs)

BIOL 1105 (26 decks)

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