advanced genetics Flashcards
(103 cards)
1
Q
who developed the principles of inheritance
A
gregor mendel
2
Q
gregor mendel performed an experiment using _____
A
pea plants
3
Q
how many crosses did gregor mendel perform
A
5,000 crosses
4
Q
how many features were expressed when two different purebred varieties of pea plants were crossed?
A
one feature
5
Q
when mendel self-fertilized the offspring, the resulting progeny expressed two different traits in a ratio of ___
A
3:1 (tall:short)
6
Q
organisms have discrete factors that determine its features
A
genes
7
Q
organism possess two versions of each factor (gene)
A
alleles
8
Q
mendel’s conclusions
A
- organisms have discrete factors that determine its features - gene
- organism possess two versions of each factor - alleles
- each gamete conains only one version of each factors - haploid
- parents contribute equally to the inheritance of offspring - fusion
- one version is dominant over the other
9
Q
each gamete contains only one version of each factor
A
haploid
10
Q
parents contribute equally to the inheritance of an offspring
A
fusion
11
Q
for each factor, one version is ____ over another and will be completely expressed if present
A
dominant
12
Q
mendel’s laws
A
- law of segregation
- law of independent assortment
- principle of dominance
13
Q
when gametes form, alleles are separated so that each gamete carries only one allele for each gene
A
law of segragation
14
Q
segragation of alleles for one gene occurs independently to that of any other gene
A
law of independent assortment
15
Q
recessive alleles will be masked by dominant alleles
A
principle of dominance
16
Q
correlated to mendel’s conclusion about genes to the behavior of chromosomes during mitosis and meiosis
A
chromosome theory of inheritance (sutton & boveri, 1902)
17
Q
chromosome theory of inheritance (sutton & boveri, 1902)
A
- chromosomes are in pairs
- homologous chromosomes separate during meiosis
- meiotic products have one of each homologous chromosome but not both
- fertilization restores the pair of chromosomes
- genes are located on chromosomes
18
Q
haploid sex cells formed by the process of meiosis
A
gametes
19
Q
males produce sperm and females produce ova
A
gametes
20
Q
during _____, homologous chromosomes are separated into different nuclei prior to cell division
A
meiosis i
21
Q
gametes are ______, meaning they only possess one allele for each gene
A
haploid
22
Q
types of zygosity
A
homozygous, heterozygous, hemizygous
23
Q
AA or aa, alleles are the same
A
homozygous
24
Q
Aa, alleles are different
A
heterozygous
25
A, only one allele
hemizygous
26
when male and female gametes fuse during fertilization, how many alleles will the resulting zygote have?
two alleles for each gene
27
which sex chromosome, as there aren't paired, only have one allele?
male, XY chromosome
28
gene composition for a specific trait; allele combination
genotype
29
either homozygous or heterozygous
genotype
30
observable characteristics of a specific trait
phenotype
31
phenotype is determined by
genotype and environmental influences
32
monohybrid cross determines the allele combinations for potential offspring for one gene only
punnett grids
33
modes of inheritance
* complete dominance
* incomplete dominance
* codominance
* multiple alleles
* sex-linked inheritance
34
considered Non-Mendelian, which means the pattern of passing trait from parent to offspring is not bound to Mendel’s laws.
modes of inheritance
35
types of complete dominance
Autosomal Dominant
Autosomal Recessive
36
types of Sex-linked Inheritance
X-linked Dominant Inheritance
X-linked Recessive Inheritance
Y-linked Inheritance
37
[complete dominance]
the dominant allele will mask the recessive allele when in a ________ state
heterozygous
38
the dominant allele will mask the recessive allele when in a heterozygous state
complete dominance
39
homozygous dominant and heterozygous forms will be phenotypically indistinguishable
complete dominance
40
[complete dominance]
the recessive allele will only be expressed in the phenotype when in a _______ state
homozygous
41
neither allele is completely dominant over the other
incomplete dominance
42
occurs when pairs of alleles are both expressed equally in the phenotype of a heterozygous individual
codominance
43
more than 2 alleles exist; occur in blood types
multiple alleles
44
which allele is **recessive and does not modify** the basic antigenic structure?
O alleles
45
which alleles are **co-dominant** and each **modify the antigen** to produce different variants?
A and B alleles
46
refers to when a gene
controlling a characteristic is located
on a sex chromosome (X or Y).
Sex linkage
47
which chromosome is
much **shorter** and contains
only a few genes?
Y chromosome
48
which chromosome is
**longer** and contains many
genes?
X chromosome
49
sex-linked conditions are usually ____, as very few genes exist on the shorter chromosome
x-linked
50
The following trends always hold true for X-linked conditions:
* only females can be carriers
* males cannot be heterozygous carriers
* males will always inherit an x-linked trait from their mother; y chromosome from their father
* females cannot inherit a x-lined recessive condition from an unaffected father; must receive his dominant allele
51
x-linked dominant disease, bent limbs and their body is unable to absorb calcium (vit d resistance)
rickets
52
x-linked dominant disease, intellectual disability, affects both male and female but females have milder symptoms
large ears, long face, prominent jaw and forehead, flat feet
fragile x syndrome
53
the manifestation of a
phenotypic trait by an allele or gene
on the Y chromosome
Y-linkage
54
are passed only from
father to son, with no genetic
recombination occurring
Y-linked traits
55
example of y-linked inheritance
hypertrichosis
56
environmental factors may also influence the expression of characteristics (Hydrangeas, human skin color)
role of environment
57
alleles that cause an organism to
die only when present in a homozygous condition
Lethal alleles
58
Lethal alleles are alleles that cause an organism to die only when present in a __________ condition
homozygous
59
An example of lethal alleles in humans; genetic condition which causes
dwarfism
achondroplasia
60
The lethal allele is __________ and hence causes the death of the organism when present in the homozygous state
dominant
61
The gene involved is considered an _____________ and the lethal allele may be either dominant or recessive
essential gene
62
_________ create altered genotypic and
phenotypic ratios
lethal alleles
63
Normally a cross of two heterozygotes will generate a 3 : 1 ratio (dominant : recessive)
lethal alleles
64
describes a condition whereby one gene controls the expression of another gene; fur color in mice; gene for baldness in humans
Epistasis
65
occurs when a single gene affects
multiple traits – hence mutations will tend to be severe and affect multiple systems
pleitropy
66
Pleiotropy can be observed in the multiple health issues arising from __________; rapid breakdown of red blood cells; clotting of sickle cells in vessels
sickle cell anemia
67
the process by which one of the two X
chromosomes present in females is inactivated
X-inactivation
68
This ensures that females do not produce twice as many
X-linked gene proteins as males
X-inactivation
69
Once an X chromosome is inactivated, it will remain permanently ______ in the cell
inactive
70
describes the presence of two
populations of cells with distinct genotypes within a single organism
Mosaicism
71
It is caused when either mutation or division error creates two distinct cell types which divide into separate cell lines
Mosaicism
72
a chart of the genetic history of a
family over several generations
pedigree
73
parents are affected; offspring is unaffected
autosomal dominant
74
parents unaffected = offspring unaffected
homozygous recessive
75
all affected individuals must have atleast one affected parent
autosomal dominant
76
unaffected parents; unaffected offspring (parents are heterozygous carriers)
autosomal recessive
77
both parents show a trait = offspring should exhibit the trait
homozygous recessive
78
if a **male shows a trait**, so must all **daughters** as well as **his mother**
x-linked dominant
79
**unaffected mother** *CANNOT* have **affected sons** (or an affected father)
x-linked dominant
80
more common in females
x-linked dominant traits
81
if a female shows a trait, so too must all sons as well as her father
x-linked recessive
82
**unaffected mother** *CAN* have **affected sons** if she is a carrier (heterozygous)
x linked recessive
83
more common in males
x linked recessive
84
groups of genetically identical organisms or a group of
cells derived from a single original parent cell
Clones
85
method by which cloned embryos can be produced using differentiated
adult cells
Somatic cell nuclear transfer
86
SCNT process
* An unfertilized egg is removed from a female adult and its haploid nucleus is removed to produce an
enucleated egg cell
* The enucleated egg cell is fused with the nucleus from the adult donor to make a diploid egg cell (with the
donor’s DNA)
* An electric current is then delivered to stimulate the egg to divide and develop into an embryo
* The embryo is then implanted into the uterus of a surrogate and will develop into a genetic clone of the adult
donor
87
used to deliver genetic material to
a target cell via horizontal gene transfer
vector
88
circular DNA molecule capable of self-replication and autonomous protein expression
plasmid
89
commonly used vector is plasmid
non-viral delivery
90
electric current is applied to make temporary holes in the cell membrane
electroporation
91
thermal energy is used
heat shocking
92
DNA coated particles are shot into the cells by a **gene gun**
particle bombardment
93
glass **micropipette** is used to inject the vector directly into a cell
microinjection
94
vector is transferred within a liposome
lipofection
95
a vesicle capable of fusion with the cell membrane
liposome
96
insertion of a viral vector into a cell is called transduction
viral delivery
97
process of gene transfer
* isolation of gene and vector
* digestion of gene and vector
* ligation of gene and vector
* selection and expression
98
DNA can be isolated from cells by centrifugation; via polymerase chain reaction (PCR)
isolating gene and vector
99
must be cut with restriction enzymes; restriction enzymes
digesting gene and vector
100
gene of interest is inserted into plasmid vector; DNA ligase, sticky ends via complementary base pairing
ligation of vector and insert
101
recombinant construct is finally introduced into an appropriate organism; transfection
selection and expression
102
In order to incorporate a gene of interest into a vector, both must be cut with restriction enzymes at specific _____.
recognition sites
103
DNA can be isolated from cells by centrifugation – whereby heavier components such as nuclei are separated. The gene of interest can then be specifically amplified via _____.
polymerase chain reaction
