Block 2 Flashcards
(170 cards)
1
Q
what is DNA fingerprinting
A
differing allele bonding pattern between individuals
2
Q
when a probe is used, we only see what area on gel electrophoresis
A
where the primer binds
3
Q
what is restriction length polymorphisms
A
change in length due to restriction enzyme activity
4
Q
what sequence does EcoRI recognize
A
GAATTC
5
Q
what is involved in western blot
A
probe protein gel with antibody probe
6
Q
what is involved in northern blot
A
probe DNA gel with RNA probe
7
Q
what is involved with southern blot
A
probe DNA gel with DNA probe
8
Q
how does gel electrophoresis differ from dot blot in the results that can be obtained
A
gel- size and charge
dot- presence/absence
9
Q
in a dot blot, DNA is added onto __ instead of to gel as in gel electrophoresis
A
blot paper
10
Q
in a dot blot, the darker the dot, the __ (greater or lower) the presence
A
greater
11
Q
what is allele specific oligonucleotides (dot blots)
A
use of a probe specific to a gene to determine presence or absence of a gene
12
Q
how do microarrays (gene chips) work
A
it contains different probes which detect different sequences at once
13
Q
what is PCR
A
in vitro DNA replication between 2 pre-determined primer sites
14
Q
what are the 3 steps to PCR
A
heat sample DNA above 92C to denature dsDNA (breaking of H bonds)
sample is cooled to 60C to anneal primers
sample is heated to 72C for DNA replication
15
Q
what is RT-PCR (reverse transcriptase-PCR)
A
production of cDNA from mRNA by reverse transcriptase
16
Q
what are microsatellites
A
repetitive DNA sequences mostly in non-coding regions
17
Q
what is dideoxy ATP
A
ATP missing the 3’ hydroxyl groups, therefore being unable to form phosphodiester bond to the next nucleotide
18
Q
what are dideoxy NTPs known as (N= any)
A
chain terminators- stop DNA replication
19
Q
what happens if DNA is synthesized in the presence of dideoxy ATP, will synthesis continue or stop
A
stop
20
Q
what occurs during G1
A
cell growth (organelles and cytoplasm double)
21
Q
what occurs during G2
A
continued cell growth
DNA checked for errors in replication
22
Q
what occurs during S of cell cycle
A
DNA replication
23
Q
what occurs during M of cell cycle
A
cell separates
24
Q
what phase of the cell cycle is G0 a part of
A
G1
25
what does the microtubule organizing center produce
spindle fibers
26
a centrosome contains 2 __ that produce __ that make up __ that connect to the __ on the __ of a chromosome
centrioles
microtubules
spindle fibers
kinetochore
centromere
27
what happens in prophase
chromosomes condense
28
what happens in prometaphase
nuclear envelope dissolves
spindle fibers form
chromosomes move towards midline
29
what dimers make up spindle fibers
alpha and beta tubulin
30
what happens during anaphase
sister chromatids separate
31
what happens during telophase
chromosomes uncondense
new nuclear membrane forms
32
5-fluoruricil acts in what phase of the cell cycle
S
33
what does 5-fluoruricil inhibit
nucleotide synthesis
34
methotrexate acts in what stage of the cell cycle
S
35
what does methotrexate inhibit
nucleotide synthesis
36
what stage of the cell cycle does bleomycin act
G2
37
what does bleomycin do
binds GC rich DNA and produces free radicals
38
what stage of the cell cycle does paclitaxel (taxol) act
M
39
what does paclitaxel (taxol) do
binds microtubule proteins
40
what stage of the cell cycle does vincristine/vinblastine act
M
41
what does vincristine/vinblastine do
bind microtubules proteins
42
what do cyclophosphamide and cisplatin do
crosslink purines in DNA
43
methotrexate inhibits production and synthesis of what
folate
adenosine
44
what stage of meiosis does crossing over occur
prophase I
45
what is the crossing over complex known as
synaptonemal complex
46
what are the 5 stages of crossing over
leptotene
zygotene
pachytene
diplotene
diakinesis
47
what occurs during leptotene of crossing over
chromosomes thin
(start of prophase)
48
what occurs during zygotene of crossing over
synapse occurs between aligned chromosomes via synaptonemal complex
49
what occurs during pachytene of crossing over
chromosomes condense enabling DNA exchange
50
what happens during diplotene of crossing over
chiasma forms
51
what happens during diakinesis of crossing over
nuclear membrane dissociates
(end of prophase)
52
what are the only 2 forms of ploidy that are viable
haploid
diploid
53
what are the only 3 viable autosomal trisomies
13 (Patau)
18 (Edwards)
21 (Down)
54
in what stage of the cell cycle does nondisjuntion occur
anaphase I or II
55
if nondisjunction occurred during anaphase I __% of the offspring would show trisomy
100
56
If nondisjunction occurred during anaphase II __% of the offspring would show trisomy
33
57
If nondisjunction occurred during anaphase I __% of the gametes would show trisomy
50
58
If nondisjunction occurred during anaphase II __% of the gametes would show trisomy
25
59
what does the G1 checkpoint check for
cell size
60
what does the G2 checkpoint check for
DNA damage
61
what does the M checkpoint check for
spindle microtubules
62
regulation of the cell cycle is through __ proteins which activate ___
cyclin
CDKs
63
__ concentrations are stable through the cell cycle, so regulation is by __ concentration
CDK
cyclin
64
cyclin binds to __ which causes phosphorylation, ___ (activating or deactivating) the protein
CDK
activating
65
when does a malignant mass matastisize
when it gets into the bloodstream and crosses tissues
66
carcinoma develops from __ tissue
epithelial
67
leukemia develops from __
blood
68
sarcoma develops from __
bones, muscles, CT
69
lymphoma develops from __
lymph
70
do proto-oncogenes go through a gain or loss of function when mutated
gain= increased cell growth
71
are oncogenes dominant or recessive
dominant
72
RET (receptor tyrosine kinase) is an example of what type of gene
oncogene
73
what is the cause of sipple syndrome (multiple endocrine neoplasia/MEN2A)
RET (receptor tyrosine kinase) mutation leading to an always on signal
74
what are the symptoms of Sipple syndrome
tumors in parathyroid and adrenal glands
kidney stones
75
how does MET (a receptor for tyrosine kinase) activate
binds hepatic growth factors
76
what carcinomas does a MET mutation lead to
hepatic and renal carcinoma
77
what type of protein is RAS (a proto-oncogene)
GTP binding
78
what happens if RAS is on
signal is sent continuously causing continuous cell growth
79
what does Philadelphia chromosome result from
translocation between 9q34 and 22q11 causing the fusion of ABL and BCR
80
what is the main cause of chronic myeloid leukemia
philadelphia chromosome
81
what is c-myc proto-oncogene responsible for
malignant cell growth
82
what does the Bcl-2 proto-oncogene do
inhibit apoptosis
83
what is the gene mutated in half of all cancers
p53
84
what is the main function of p53
stop the cell cycle or cause apoptosis if repair is not possible
85
for initiation of apoptosis in p53, there is increase in activity of __ and decrease in activity of __
Bax
Bcl-2
86
tumor suppressor gene mutations lead to a gain or loss of function
loss of function
87
retinoblasta (Rb) controls what checkpoint of the cell cycle
G1
88
if Rb is hypophosphorylated, E2F transcription factor is active or inactive
inactive
89
what is E2F required for
progression through G1
90
what checkpoint does p53 act in
G1
91
NF1 tumor suppressor gene inactivates __, leading to __ (increased or decreased) cell division
Ras
decreased
92
are tumor suppressor proteins dominant or recessive
recessive
93
what does the two-hit hypothesis say
a mutation in one allele won't cause cancer on it's own but a mutation in a second results in a 2 hit
94
removal of a functional allele leads to the cell being ___
hemizygous (loss of heterozygosity)
95
Wilms tumor in children is due to what
loss of heterozygosity
96
a methylated tumor suppressor gene is active or inactive
inactive
97
what cause Lynch syndrome
failure of mismatch repair in transcription
98
in a pedigree, the first individual to be identified to be affected is called the __
proband
99
how do you identify an autosomal dominant on a pedigree chart
non gender specific
present in all generations
100
what is recurrence risk
the probability that the offspring will express genetic disease
101
what are 5 examples of autosomal dominant diseases
familial hypercholesterolemia
huntingtons
hemolytic anemia
acute intermittent porphyria
neurofibromatosis
marfan syndrome
A
Dominant
Family
Hugs
Happily
At
New
Marriages
102
how to identify autosomal recessive on a pedigree
not in every generation
non-gender specific
103
a homozygote child is most often produced by the mating of mom__ and dad__ for autosomal recessive disease, leading to __% of offspring affected
heterozygous
heterozygous
25
104
what is consanguinity
sharing a common ancestor
105
what are 4 examples of autosomal recessive diseases
sickle cell anemia
cystic fibrosis
tay-sachs
phenylketouria
A Recent Sick Child Takes Food
106
is male to male transmission seen in x-linked recessive
no, dad will donate Y chromosome
107
what are 7 examples of X-linked recessive diseases
red green color blindness
Lesch-Nyhan syndrome
duchenne muscular dystrophy
menke's disease
G6PD deficiency
ornithine transcarbamoylase (OTC) deficiency
hemophilia A and B
X-Relatives Rarely Love Doing Me Good, Only Hate
108
what type of mutation is duchenne muscular dystrophy
frameshift
109
what are the symptoms of duchenne muscular dystrophy
waddling gait
gower sign
110
what is the Gower sign seen in muscular dystrophy
use of upper extremities to help stand up
111
when is duchenne muscular dystrophy diagnosed
1.5-2 years when child should start to walk
112
what type of inheritance is Becker muscular dystrophy
X linked
113
what type of mutation is Becker muscular dystrophy
nonframeshift deletion (insertion, deletion, or missense)
114
why does Becker muscular dystrophy present less severe than Duchenne
duchenne is a frameshift mutation (everything after the point of mutation is affected)
Becker is a nonframeshift mutation so there is milder and slower clinical progression
115
what is X inactivation/lyonization
dosage compensation to equalize the amount of protein encoded by X chromosome in males and females through epigenetic silencing
116
X inactivation is seen as a __
Barr body
117
what does it mean to say females are mosaic in regards to the active X chromosome
one whole X or half of one X, half of the other X
*can be different in each cell but once the decision is made, it continues in that cell through all it's divisions
118
X chromosome inactivation is permanent in __ cells and reversible in __ cells
somatic
germ line
119
Barr bodies are composed of ___ through __
heterochromatin
methylation
120
methylation of regions on the X chromosome is a method of ___
epigenetic silencing
121
what type of inheritance can manifesting heterozygotes be seen
X linked recessive disease
122
what is involved in females as manifesting heterozygote
female displays x linked recessive trait due to skewed lyonization
123
what is an example of X linked dominance disease
fragile X
124
what are the symptoms of fragile X
mental retardation
large ears
macro-orchidism
large jaw
125
what is the most common inherited cause of mental retardation
fragile X
126
what does a dominant X disease look like on pedigree
no male-male transmission
non-gender specific
127
what is mitochondrial inheritance transmission
transmission occurs only through affected mothers to all children
128
what is heteroplasmy seen during mitochondrial inheritance diseases
a mutation occurs in some mitochondria, causing an uneven distribution of mutated mitochondrial to the offspring
the SEVERITY of mitochondrial disease differs based on the amount of mutated mitochondria the offspring received from mother
129
what are 3 examples of mitochondrial inheritance diseases
MELAS
MERRF
Leber hereditary optic neuropathy
130
what is allele heterogeneity
different mutations within the same locus leading to multiple mutant alleles and different diseases
131
what is penetrance
percentage of individuals who have gene and show the phenotype
ex: 100 individuals with gene, 75 show physical feature= 75%
132
what is incomplete penetrance
someone who has the genotype but does not show they phenotype
*disease is present but did not present
133
what is pleiotropy
one gene having many different effects
134
marfan syndrome is an example of __ due to exhibition of problems in multiple organ systems such as in joints, eyes, heart, and skeleton
pleiotropy
135
what is locus heterogeneity
mutations on different locus leading to the same disease
ex: mutation on chromosome 7 or 17 both result in osteogenesis imperfecta
136
what are 3 factors involved in anticipation
increase in disease severity
earlier onset of disease
increase in trinucleotide repeats
*trinucleotide expansion mutation is the main indicator
137
Huntington disease expansion is present on which chromosome number
4
138
what are the symptoms of huntington disease
movement abnormality
emotional disturbance
cognitive impairment
death 10-15 after onset
139
what are 4 examples of anticipation diseases
huntingtons
fragile X
myotonic dystrophy
Friedreich ataxia
140
what are symptoms of myotonia dystrophy
muscle loss
cardiac arrhythmia
testicular atrophy
frontal baldness
cataracts
141
what are symtpoms of Friedreich ataxia
ataxia
hypertonic cardiomyopathy
axonal sensory neuropathy
kyphoscoliosis
142
Prader Willi syndrome is caused by what
deletion on paternal chromosome 15q of an imprinted locus
143
Angelman syndrome is caused by what
deletion on maternal chromosome 15q of an imprinted locus
144
imprinting involves what epigenetic silencing mechanism
methylation
145
what are 3 symptoms of prader willi syndrome
failure to thrive at birth but overtime (1-2 years) leads to obesity with developmental and mental delay
almond shape eyes
146
the gene that is missing in prader willi (15q) normally encodes for what
component of mRNA splicing
147
the gene missing in angelman syndrome normally encodes for what
ubiquitin pathway gene
148
what test is used to test for deletion on paternal/maternal chromosome 15
fluorescence in situ hybridization (FISH)
149
what is a symptoms for angelman syndrome
puppet-like posture of limbs
150
what are the 2 possible genetic caused of prader willi and angelman syndrome
imprinting and deletion
uniparental disomy
151
what is uniparental disomy
2 copies of a chromosome come from one parent instead of a copy from both mom and dad
*one parent gives extra, one parent gives none
152
what is cytogenetics
change in a chromosome that is large enough to be seen through a microscope (ex: extra or loss of chromosome)
153
karyotypes visualize chromosomes in what stage of mitosis
metaphase
154
what is G-banding
use of Giemsa dye that binds DNA to visualize chromosome banding pattern based on heterochromatin (dark) and euchromatin (light)
155
what is the difference between karyotypes and FISH
karyotype used for large deletions
FISH used for microdeletions
156
acrosentric chromosomes appearance
little p arm, big q arm
157
what chromosomes are acrocentric
13, 14, 15, 21, 22
158
what are 2 major forms of aneuoploidy
monosomy (loss of a chromosome)
trisomy (gain of a chromosome)
159
how is trisomy 21 written
47, XY, +21
47, XY, +21
160
what are the main symptoms of Down syndrome
short stature
epicanthal fold
clinodactaly (abnormal bent/curved fingers)
flat facial profile
depressed nasal bridge
epicanthal fold (upper eyelid skin fold covers the inner corner of they eye)
single transverse palmar crease
brushfield spots are margin of iris
161
what are 4 common comorbidities of Down syndrome
Alzheimer disease (early onset due to 3 copies of amyloid precursor protein gene)
acute lymphoblastic leukemia
duodenal atresia
atrial septal defects
162
what are 2 the main tests for Down syndrome
karyotype
quadruple test
163
what are the 4 markers found in the quadruple test that indicates high risk for Down syndrome
during 2nd trimester screening test there is:
increased hCG (above reference range)
increased inhibin A
decreased unconjugated estriol
decreased alpha-fetoprotein (AFP)
164
how is trisomy 18 written
47, XY, +18
47, XX, +18
165
what are the main symptoms of Edward syndrome (trisomy 18)
clenched fist with overlapping fingers
rocker-bottom feet
elongated skull
webbing of 2nd and 3rd toes
*joint defects (contracture- curving)
166
what is arthrogryposis
congenital joint curving in 2 or more areas of the body
*seen in Edward syndrome
167
how is trisomy 13, Patau syndrome, written
47, XY, +13
47, XX, +13
168
what are the main symptoms of Patau syndrome
cleft lip/palate (midline fusion defects)
polydactyly
*more severe/midline defects
169
what are the 4 markers found in the quadruple test that indicates high risk for Edwards syndrome
during 2nd trimester screening test there is:
normal inhibin A
decreased hCG (above reference range)
decreased unconjugated estriol
decreased alpha-fetoprotein (AFP)
170
what are the 4 markers found in the quadruple test that indicates high risk for Patau syndrome
during 2nd trimester screening test there is:
decreased hCG (above reference range)
normal inhibin A
normal estriol
normal alpha-fetoprotein (AFP)
