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Genetics > Lecture 2a and b: Chromosomes > Flashcards

Lecture 2a and b: Chromosomes Flashcards

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1
Q

Simple Mendelian Inheritance involves what gene to allele ratio

A

1 single gene with 2 different alleles

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2
Q

When studying human traits, it’s not ethical to control parental crosses (like Mendel and pea). Rather we rely on information from…

A

Pedigrees

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3
Q

Used to determine the pattern of inheritance of traits in humans

A

Pedigree analysis

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4
Q

For something to be autosomal recessive disease, it must be…

A

homozygous

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5
Q

Examples of an autosomal recessive disease?

A

Sickle cell anemia, CF

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6
Q

A minority of human diseases are causes by….

A

dominant mutations

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7
Q

For something to be a dominant mutation, an affected individual needs to have…

A

only inherited one copy of the mutant gene from an affected parent

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8
Q

Dominant mutations cause a ___ pattern of inheritance

A

dominant

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9
Q

Example of an autosomal dominant disease

A

Huntingtons disease (neurodegenerative disease)

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10
Q

p53 is a ____, if ___ or more units are mutated—the protein doesn’t work

A

tetramer, 1

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11
Q

Dominant negative mutation example

A

p53 is a protein that prevents cancer, but in more than 50% of cancers, it is mutated

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12
Q

Most p53 mutations are…

A

simple loss of function (both copies of gene deleted)

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13
Q

Gain of function mutation example

A

Ras promotes cell division. Mutated in 20% of cancers and is overactive

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14
Q

The common explanations for dominant disorders are…

A
  1. Haploinsufficiency
  2. Gain of function mutations
  3. Dominant negative mutations
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15
Q

The heterozygote has 50% of the normal protein in _____. However, you need the total protein to be fine.

A

Haploinsufficiency

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16
Q

Mutation changes the protein so it gains a new function

A

gain of function mutation

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17
Q

the altered gene product acts antagonistically to the normal product

A

dominant negative mutations

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18
Q

Many genetic diseases are inherited as ____, where the mutant genes responsible have been cloned and mapped.

A

autosomal dominants

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19
Q

Female is the carrier but the male gets the disease

A

X linked genes

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20
Q

A ____ for an X linked disease shows mostly ___ affected with their mothers as carriers

A

pedigree, males

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21
Q

Example of an X linked gene

A

Muscular dystrophy and hemophilia

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22
Q

Traits where one allele is dominant in one sex but recessive in the opposite sex

A

Sex influenced traits

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23
Q

Sex influence is a phenomenon of

A

heterozygotes

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24
Q

Most sex influenced traits are….

A

autosomal

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25
Ex. of sex influenced traits
baldness
26
Bb and BB mean there will be balding, but bb means there will not. Allele B behaves ___ in males and ___ in females.
dominant, recessive
27
Pattern baldness results from the expression level of a gene that converts....
testosterone to 5-DHT
28
Testosterone levels are ___x more in males than females
5
29
The heterozygous exhibits a phenotype that is intermediate between the corresponding homozygotes.
Incomplete dominance
30
Example of incomplete dominance
A red homogenous flower and white homogenous flower make a pink heterozygous flower
31
An allele is dominant in some heterozygous individuals but not in others
Incomplete penetrance
32
Example of incomplete penetrance
polydactyly
33
polydactyly is what kind of trait
autosomal dominant (only need one mutant copy)
34
The measure of penetrance is described at what levek?
population
35
In incomplete penetrance, if 60% of heterozygotes are carrying a dominant allele exhibit the alleles trait, the trait is ___ penetrant
60%
36
In most cases with incomplete penetrance, the range of phenotypes is thought to be due to influences of the...
environment and/or genes
37
Phenomenon where a heterozygote is more vigorous than either of the corresponding homozygote
Overdominance
38
Sickle cell anemia is what kind of disorder
Autosomal recessive
39
Ex. of overdominance
Sickle cell anemia. If you are heterozygote you are resistant but if you are homozygote---you get it.
40
Over dominance is due to, at the molecular level...
to two alleles that produce slightly different proteins
41
Enviornmental conditions may have a great impact on the ___ of the individual
phenotype
42
By geneticists examining a range of conditions in regards to environmental conditions, this allows them to see the ____ of the environmental influence on phenotypic range.
norm of reaction
43
There are multiple alleles that exhibit a...
dominance hierarchy
44
Coat colors in rabbits is an example of...
4 dif alleles that exhibit dominance hierarchy
45
Himalayan pattern of coat color in rabbits is an example of a....
temperature sensitive conditional allele
46
Produced by the immune system that bind to things that are foreign to the body. The binding signals WBC to destroy the foreign thing
Antibody
47
Something that is recognized by the immune system antibodies
antigen
48
Example of multiple alleles with co-dominance
ABO blood group (A and B dominant over O)
49
The ABO blood group is determined by the...
type of antigen present on the surface of RBC
50
AB blood groups are expressed in a ____ person
heterozygous
51
O blood group represents a...
loss of function
52
Determined by the type of carb antigen (sugar) recognized on the surface of....
ABO blood group, RBC
53
Antigens ___ arises when a sugar is added to a sugar chain already in the surface of the RBC by an enzyme controlled by the allele of the I gene
A and B
54
Allele i is a __allele that is ___ to both IA and IB in ABO blood group
null, recessive
55
An allele that has the potential to cause the death of an organism
lethal
56
Lethal alleles are typically the result of mutations in....
essential genes
57
Many lethal alleles prevent ____.
cell division
58
May kill an organism only when certain environmental conditions prevail
conditional lethal alleles
59
The situation where the alleles of one gene can mask the phenotypic effects of the alleles of another gene
Epistasis
60
When genes in the same pathway, but one gene comes before the other and masks the effects of the gene after it
epistasis
61
Plays a role in coat color in rodents, two true breeding parents are crossed and become ____. The F1 ____ is crossed and produces what ratio?
epistasis, agouti animals, 9:3:4
62
At least one copy of each dominant results in ____ color
agouti
63
Refers to one gene influencing 2 or more seemingly unrelated phenotypic traits
Pleiotropy
64
Occurs when both parents express the same, or similar recessive phenotypes but produce offspring with a wild-type phenotype
complementation
65
Example of complementation
White flowers homozygous (CCpp) and (ccPP) are crossed to make a purple heterozygous flower (CcPp)
66
Occurs when one gene can compensate for the loss of function of another
Gene redundancy
67
Gene redundancy can be due to...
gene duplication
68
Duplicate genes are called
paralogs (not always the same)
69
Example of gene redundancy
seed shape, 15:1 ratio, dominant allele will give triangle
70
Refers to a pattern in which modification occurs to a nuclear gene or chromosome that alters gene expression
epigentic inheritance
71
What does not change over many generations
DNA sequence
72
Two ways to obtain epigenetic inheriteance
1. chromosomal dna is not naked in cell but covered in proteins that stick to it. gene copies are expressed different because proteins are binding the copies of the gene different. 2. chromosomal dna can be chemically modified by added methyl group
73
Adding a methyl group onto chromosomal dna has what effect?
cause genes to be less expressed or turned off
74
Phenomenon in which expression of a gene depends on whether it is inherited from the mom OR dad
Genomic imprinting
75
Genomic imprinting is another example of...
monoallelic expression
76
The slient allele in genomic imprinting is known as
imprinted allele
77
Random X inactivation is an example of
monoallelic expression
78
Epigenetic inheritance allele is expressed in euchromatin
monoallelic expression
79
In random x inactivation, the chromosomes become....
more condensed and a barr body is formed
80
Imprinting results in the expression of the ___ but not the ___ allele
paternal, maternal
81
The imprinted allele is the silent one so that Igf2 gene is...
maternally imprinted
82
Dosage compensation occurs when ___ is not expressed
X in males
83
Dosage compensation is only epigenetic inheritance in...
marsupials
84
X inactivation brings about....
Dosage compensation
85
The purpose of Dosage compensation is to....
offset the differences in the number of genes on the sex chromosomes
86
X-linked gene dosage compensation in human females occurs by:
condensation throughout one of the two X chromosomes in females to form a ‘Barr Body’
87
Klinefelters syndrome
male XXY
88
Turner syndrome
X0, female
89
Triple X syndrome
XXX, female
90
The ____ it the thing that binds the sister chromatids of a chromosome originally inherited from mom to the sister chromatids of a homologous chromosome inherited from dad
synaptonemal complex
91
Cell not in cell cycle is in
G0
92
Incomplete dominance occurs because A. a gene is found on the X chromosome B. the dominant allele is not expressed due to environmental effects C. 50% of the normal protein is not enough to produce the same phenotype as 100% of the protein. D. the recessive allele inhibits the expression of the dominant allele
C
93
Chloroplasts originated as
cyanobacteria
94
mitochondria originated as
nonsulfer purple bacteria
95
The endosymbiotic origin of organelles is supported by what observations?
organelles have circular chromosomes (like bacteria) Organelle genes are more similar to bacterial genes than to those in the nucleus.
96
Chloroplasts are only inherited from the ___. What kind of leaves?
mother, white or variegated
97
Mitochondria are inherited from
mom
98
Mitochondrial mutations may occur in ____cells. Why?
somatic; they are susceptible to DNA damage
99
protein recruits proteins to create a new bacterial cell wall
FtsZ protein

Genetics (11 decks)

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