midterms 25% Flashcards
(165 cards)
1
Q
● A condition when during the heterozygous
condition (Bb) the dominant allele does not
completely overpower the recessive allele.
● Therefore, there is a “blending” of the traits.
A
incomplete/partial dominance
2
Q
A condition when during the heterozygous
condition (Bb) the dominant allele does not
completely overpower the recessive allele so
both traits are seen at the same time.
- No recessive allele at all
A
codominance
3
Q
This occurs when both alleles are
expressed equally in the phenotype of the
heterozygote.
A
Codominance
4
Q
● Inheritance pattern for traits that are controlled
by more than one gene.
● An example would be: height, skin complexion,
eye color, hair color, etc.
A
polygenic inheritance
5
Q
● Genes capable of causing death of organism
carrying them
- Typically the consequence of mutation
A
lethal genes
6
Q
Manx cats are heterozygous for a dominant mutation that
results in no tails (or very short tails), large hindlegs, and a distinctive gait. The mating of two Manx cats yields two Manx kittens for each normal, long-tailed kitten, rather than 3:1 as would be predicted from Mendelian genetics. Therefore, the mutation causing the Manx cat phenotype is likely a(n)
_____ allele.
a. Codominant
b. Epistatic
c. Lethal
d. Sex-linked
A
lethal
7
Q
● When one gene affects multiple characteristics.
● It refers to the expression of multiple
traits by a single gene.
A
Pleiotropy
8
Q
- The transmission of traits through cytoplasmic genetic factors such as mitochondria or chloroplasts.
■ These cytoplasmic organelles are usually inherited with the egg’s cytoplasm from the mother
A
● Maternal inheritance (also called cytoplasmic
inheritance)
9
Q
- An individual’s phenotype is controlled
by gene products in the genome (e.g.
proteins) of the mother (oocyte).
A
Maternal effects (also called maternal
influence)
10
Q
A cell with a mutant and normal
mitochondria
A
heteroplasmy
11
Q
A cell has a uniform set of
mitochondria: all completely
normal mtDNA or completely
mutant mtDNA
A
homoplasmy
12
Q
Only the mother pass on the
mitochondrial DNA
true or false
A
true!
13
Q
- a complementary cross
between the phenotypes of the female and the
male
A
Reciprocal cross
14
Q
● Refers to the inheritance of an agent
(microorganisms, parasites, viruses, bacterias,
etc.) that can be inherited with cytoplasm.
A
INFECTIOUS INHERITANCE
15
Q
_______ are formed due to the differential
methylation of paternal and maternal alleles.
A
Imprints
16
Q
- low levels of gene
expression - Genes are imprinted
- Not expressed at all
A
Methylated DNA
17
Q
- higher level of gene
expression - Genes are not imprinted
- Will be expressed
A
Unmethylated DNA
18
Q
Presence of two or more populations of cells
with different genotypes in one individual who
has developed from a single fertilized egg.
A
mosaicism
19
Q
This can be a result of X-inactivation or
mutation
- Both could lead to the development of
multiple cell populations
A
mosaicism
20
Q
It develops during early
stage of embryonic development
(development of multiple cell
populations)
A
Mosaicism
21
Q
it can be seen usually on the
later stage of life or when the individual
was already born
A
Vitiligo
22
Q
refers to the
marking process in which an offspring
expresses a gene that is inherited from
one parent but not both.
A
Genomic Imprinting
23
Q
used to analyze the patterns of
inheritance of a particular trait that runs in the
family.
A
Pedigrees
24
Q
Use a__________ if the gender is not yet known, a
circle or a square if the gender is known.
A
diamond
25
○ If the trait is ________, one of the
parents must have the trait.
dominant
26
__________ traits skips the generation of
the affected family.
Recessive
27
✔ Only males are affected
Sex linked
28
✔ Parents doesnt have to be affected
✔ Skips generation (meron sa anak, sa parent
wala)
Sex linked recessive
29
✔ Does not skip a generation
Autosomal dominant
30
- One mutated copy of the gene in each cell is
sufficient for a person to be affected
- Each affected person usually has one affected
parent
Autosomal dominant
31
- Two mutated copies (homozygous) of the gene
are present in each cell
- Affected person usually has unaffected parents
who each carry a single copy of the mutated
gene (and are referred to as carriers)
Autosomal recessive
32
● Associated diseases are located in the X
chromosomes
X-LINKED DOMINANT INHERITANCE
33
- Always expressed in the males
- Expressed in a female homozygote but very
rarely in a heterozygote
X-linked Recessive trait
34
● Only males are affected
● It is based from father to all sons
- Because it is y-linked
● It does not skip generations
Y-linked Dominant
35
● Appears in both sexes with equal frequency
● Trait tend to skip generations
● Affected offspring are usually born to unaffected
parents
Autosomal Recessive
36
If most of the males in the pedigree are
affected, then the disorder is ?
X-linked
37
If it is a 50/50 ratio between men and women
the disorder is?
autosomal
38
● Both males and females are affected; often more
females than males are affected
● Does not skip generations.
● Affected sons must have an affected mother
X-linked Dominant
39
● Affected daughters must have either an affected
mother or an affected father
● Affected fathers will pass the trait on to all their
daughters
● Affected mothers if heterozygous will pass the
trait on to 1/2 of their sons and 1/2 of their
daughters
X LINKED DOMINANT
40
● It is NEVER PASSED FROM FATHER TO SON
● All daughters of affected fathers are carriers
X LINKED RECESSIVE
41
occurs when a homologous
pair of chromosomes fails to disjoin or separate
during cell division.
Nondisjunction
42
________ NONDISJUNCTION
● Failure of the chromosomes to disjoin and pass
to opposite poles
● Major cause of chromosomal abnormalities
MEIOTIC
43
● 75% occurs in oogenesis, where the
probability of nondisjunction increases with
maternal age
● Almost 80% occur in the first meiotic division
meiotic nondisjunction
44
During this stage, sister copies of DNA are
supposed to break apart and chromosomes are pulled
by the spindle
Anaphase
45
describes the chromosomal
complement of an individual.
Karyotype
46
petit, short arm
p
47
p-arm
○ Region 1
■ Contains __ band
1 band
48
p-arm
○ Region 2
■ Contains __ bands
2 bands
49
q-arm
○ Region 1
■ Contains __ bands
3 bands
50
q-arm
○ Region 2
■ Contains __ bands
8 bands
51
69, XXX ; 69, XXY ; 69, XYY
- 3 sets of chromosome
- Happens when ovum is fertilized by 2
sets of sperm
TRIPLOIDY
52
4, XX,+21
- Gain of 1 chromosome
TRISOMY
53
45,X
- 1 chromosome is missing
MONOSOMY
54
47,XXX / 46,XX
- 2 population of cells: 1 with trisomy, 1
normal cells
MOSAICISM
55
________ deletion - 1 break in the chromosome
→ chromosome segment distal to the break gets
detached and is lost
Terminal
56
_________ deletion - 2 breaks in the
chromosome → chromosome segment distal to
the break gets reattached
Interstitial
57
● 2 breaks in the chromosome arm (pwedeng both
arm or isang arm lang)
● Nagflip upside down yung segments tsaka siya
nag reattach
INVERSION
58
When the inversion involves BOTH arms and involves the centromere
PERICENTRIC INVERSION
59
When the inversion involves ONLY ONE arm
PARACENTRIC INVERSION
60
This involves the long arm of chromosome 1 region 2 band 2; has two segments
duplication
61
● The chromosome break, another chromosome
break
translocation
62
● The break occurs in the arm and they are fused
with each other
● The fragment that was cut off are lost during cell
division and it loses genetic material
ring chromosome
63
46.XY,r(9)(p12q21)
RING CHROMOSOME
64
formed when you have 1 break on its
arm: both in short and long arm, and the two
ends of the two arms fuse together because
they are sticky forming a ______ at the centromere
ring chromosome
65
46,XX,del(5)(q13q33)
interstitial
66
46,XY,del(4)(p16.3)
terminal
67
Abnormalities based on cell chromosomal
constituent are
1.
2.
○ Constitutional
○ Somatic or acquired
68
________ ABNORMALITY
● Found in ALL cells of the body
● Occurs very early in development
CONSTITUTIONAL
69
_________ ABNORMALITY
● Present only in CERTAIN tissues or cells
● Cell types with different chromosome
compositions
SOMATIC OR ACQUIRED
70
Abnormalities in chromosomes are produced
by the following, EXCEPT:
a. Misrepair of broken chromosomes
b. Improper recombination
c. Erroneous segregation during cell
division
d. DNA mutation
DNA MUTATION
71
Nondisjunction that occurs during meiosis II
will NOT result in which of the following
chromosome number in the zygote?
a. Normal
b. Monosomy
c. Nullisomy
d. Trisomy
NULLISOMY
72
Meiotic nondisjunction is more commonly
seen among which of the following?
a. Increasing maternal age
b. Increasing paternal age
c. Post-radiation in the young
d. Maternal infection
Increasing maternal age
73
Single gene mutation is increased in which
of the following?
a. Oogenesis in elderly women
b. Spermatogenesis in elderly men
c. Both
SPERMATOGENESIS IN ELDERLY MEN
74
Which of the following outcomes of
anaphase lag is almost always not
compatible with embryogenesis or live birth?
a. Monosomy of sex chromosomes
b. Trisomy of sex chromosomes
c. Monosomy of autosomes
d. Trisomy of autosomes
Monosomy of autosomes
75
GIVE THE KARYOTYPE
Female with classic Trisomy 21
47,XX,+21
76
Give the karyotype of Male with terminal deletion of chromosome 3, short arm, region 2, band 3, sub-band 1
- 46,XY,del(3)(p23.1)
77
45,X means
a female with monosomy X
78
Karyotype of a female with triploidy
69,XXX / 69,XYY
79
Karyotype of a female with triploidy
69,XXX / 69,XYY
80
A female with balanced reciprocal
translocation with breakpoint in the long arm
of chromosome 7, region 2, band 3 and the
short arm of chromosome 10, region 3 band
2 sub-band 1
- 46,XX,t(7;10)(q23;p32.1)
81
individuals with a normal set of
chromosomes; no extra or missing; normal
human somatic cells are diploid, with two sets of
23 chromosomes
Euploidy
82
- with extra sets of chromosomes;
caused by fertilization of an egg by > 1 sperm;
not compatible with life; e.g. triploidy (69,XXX).
Polyploidy
83
- two or more genetically different
cell lines
Mixoploidy
84
- with two cell populations
originating from the same zygote
Mosaic
85
- arise from two different zygotes
Chimera
86
- missing a pair of homologs
occuring during the preimplantation stage; lethal.
○ During this stage, baby may be aborted
Nullisomy
87
- one chromosome missing; occurs
during embryonic stage; lethal and abort in 99%
of cases;
Monosomy
87
- one chromosome missing; occurs
during embryonic stage; lethal and abort in 99%
of cases;
Monosomy
88
- gain of one chromosome: occurs
during embryonic (1-2 weeks) or fetal (9-36
weeks) stage;
Trisomy
89
In NONDISJUNCTION,
1st Meiotic division results to = __ normal zygotes, 1
trisomic, __ monosomic
2 normal zygotes, 1 trisomic, 1 monosomic
90
In NONDISJUNCTION,
2nd Meiotic division = __ trisomic zygotes, 1
monosomic
1
91
● May occur at G1 (affects both chromatids) or
G2 (affects one chromatid) phase of cell
cycle.
STRUCTURAL ABNORMALITIES
92
_____systems in the cell recognize and repair
broken chromosomes
Enzyme
93
Repair can be either by joining the two ends or
??
capping ends with telomeres
94
-
healed by adding telomere, if near the
telomere
Single break (terminal deletion)
95
- ring chromosome formation, duplication, interstitial deletion, inversion, translocation
Two or three breaks
96
two breaks -> broken portion turned
upside down -> reattached
○ No loss or gain of genetic material ->
inversion carriers, normal
INVERSION
97
- inversion of a
segment of the p or q arm and DOES NOT
include the centromere
Paracentric inversion
98
- breaks occur in
both short and long arms and INCLUDES
the centromere in the inverted segment
Pericentric inversion
99
- loss of a segment of a chromosome;
2 breaks between the centromere and telomere
-> loss -> fusion of broken ends
Deletion
100
- transfer of a chromosome
segment to another chromosome
Translocation
101
involves exchange of genetic materials of non-homologous chromosomes
○ No loss or gain of chromosomes but with gene rearrangement -> physically And mentally normal
Reciprocal or balanced translocation -
102
_________ translocation - involves
acrocentric chromosomes which have short p
arms called satellites
Robertsonian
103
_________ translocation - involves
acrocentric chromosomes which have short p
arms called satellites
Robertsonian
104
Robertsonian translocation - involves
acrocentric chromosomes which have short p
arms called ?
Satellites
105
○ The two p arms or satellites are lost because they are not attached to a spindle fiber during mitosis
○ Total chromosome is 45 due to fusion of the two chromosomes
Robertsonian translocation
106
Acrocentric chromosomes are __ 14,
15, __ and __ with short arms
(satellites) made up of rRNA
13, 14, 15, 21 AND 22
107
-
occurs when the exchange of chromosome
material is UNEQUAL resulting in loss or gain of
genes
○ Causes significant clinical outcomes
Nonreciprocal or unbalanced translocation
108
- chromosomes with two identical arms
○ Arms mirror image of each other; both p or q arms
Isochromosomes
109
● Study of chromosomes and their heredity
● The study of the physical size, structure,
and behavior of chromosomes.
CYTOGENETICS
110
○ Dark stain regions -
heterochromatin
111
Lightly stain regions -
euchromatin
112
○ Dark bands
○ Heterochromatic
○ Rich in the base pairs A-T (Adenine
and Thymine)
○ Devoid or with inactive genes
G-BANDS
113
○ Pale or bright bands
○ Euchromatic
○ Rich in G-C (Guanine and Cytosine)
○ Genes actively expressed
G negative bands
113
○ Pale or bright bands
○ Euchromatic
○ Rich in G-C (Guanine and Cytosine)
○ Genes actively expressed
G negative bands
114
● Fluorescent dye (Quinacrine, DAPI,
Hoeschst 3328)
● Patterns are similar to G banding
● Uses fluorescent microscope
Q-BANDING
115
● A-T rich (fluorescing, heterochromatin)
● G-C rich (light regions, euchromatin)
● Applied for rapid ID of Y chromosome in
uncertain genitalia
Q-BANDING
116
● Reverse of G-banding pattern
● Chromosomes are denatured by heat
before staining with Giemsa
● Patterns are similar to G banding
R-BANDING
117
● Heat denatures = A-T rich (bright)
● Dark regions - G-C rich (euchromatin)
● Used to detect deletion of telomeres
which are dark bands
R-BANDING
118
● Severe heat prior to staining (Giemsa or
combination of dye and fluorochromes)
● Identifies telomeres
T-BANDING
119
● Giemsa
● Treated with alkali solution
● Stains centromeres
C-BANDING
120
○ Most common SPECIMEN USED FOR
CYTOGENETIC TECHNIQUES
○ Preferred specimen for routine
cytogenetic studies of adult and
children
Heparinized peripheral blood
121
○ Used in studying hematologic disorders
Bone marrow aspirates
122
○ Used in Fibroblast cultures
Skin biopsies
123
○ Most common specimen for prenatal
analysis
Amniotic fluid
124
Fetal blood from the umbilical cord
○ Useful in ??
rapid karyotyping
125
Chorionic villus is used for
prenatal analysis
126
Chorionic villus is used for
prenatal analysis
127
Tissues such as kidney, liver, muscle, and lung should be handled and transported with?
ice
128
Excellent sources if obtained soon after death during autopsy or from a fetal loss
Tissues such as
kidney, liver, muscle,
and lung
129
○ Single enzyme or multiple enzymes
synthesize copies of target nucleic
acid
Target amplification
130
○ Most mature and widely used nucleic acid amplification method
○ In vitro chemical reaction that permits the synthesis of essentially limitless quantities of a targeted nucleic acid sequence
○ Uses DNA polymerase
Polymerase Chain Reaction
131
○ Amplification products contain a sequence only present in the initial probes
Probe amplification
132
○ The concentration of the probe or target does not increase
○ Concentration of label molecu;es attached to target nucleic acid increases
○ Uses multiple enzymes and probes with reduction of background noise to enhance target detection
Signal amplification
133
A heat-stable DNA polymerase
An equimolar mixture of dNTPs
- (dATP, dCTP, dTTP)
pcr
134
● DNA polymerase synthesizes a new DNA strand complementary to the DNA template in 5’ to 3’ direction
Extension/Elongation (72°C)
135
● Cooled to permit the primers to anneal the target DNA in a sequence specific manner
● Polymerase binds to the primer-template hybrid and begins DNA synthesis
Annealing (50 - 65°C for 20-60 secs)
136
● Reaction mixture is heated to separate 2 strands of target DNA
Denaturation (94 - 98°C for 20-30 secs)
137
● Amplify ribonucleic acid (RNA) targets
● Complementary (cDNA) is produced first
from RNA targets, then cDNA is amplified
by PCR
● Detection/quantification of hepatitis C virus
(HCV) RNA and HIV-1
rt pcr
138
● Target amplification and detection steps
occur simultaneously in the same tube
● PCR product is detected as it is
produced
REAL-TIME (HOMOGENOUS, KINETIC)
POLYMERASE CHAIN REACTION
139
● Fluorescent dyes that preferentially bind to
double-stranded DNA (dsDNA)
● Decrease time required to perform nucleic
acid assays because there are no
post-PCR processing steps
REAL-TIME (HOMOGENOUS, KINETIC)
POLYMERASE CHAIN REACTION
140
● Use of DNA probes on a chromosome spread.
● Used to detect and localize the presence or
absence of specific DNA sequences on
chromosomes
FISH
141
________FISH
- Uses a computer assisted system
- E.g: Dual fusion probes
Multicolor
142
________Karyotyping (SKY)
- Identify the chromosome using chromosome with same colors
- Multiple chromosomal aberrations
- White arrows identify some of the chromosome translocations
Spectral
143
- Uses a telomere probe → recognize 6 base repeat present at the ends of the chromosome
- Confirms the presence or absence of telomeric regions
ALL-TELOMERE FISH
144
- Involves only co-hybridization of 2 DNA samples
- Detects the copy number variation (CNV) of a DNA sequence
Comparative Genomic Hybridization
145
- Directly compares the DNA content
of differentially labeled normal and
tumor cell population by their
co-hybridization to normal
metaphase chromosome spreads
Comparative Genomic Hybridization
146
○ Comparison of labeled normal and tumor cells by their hybridization to a series of genomic oligonucleotides
aligned on a glass slide that serves as probes
○ Hundreds to thousand of features can be placed in 1 solid surface
Microarray Hybridization/DNA Chip
Technology
147
● Injection of a monodisperse suspension of particles (cells) into the center of a flowing stream of fluid (sheath)
● Passing through a small quartz capillary tube at a constant velocity
FLOW CYTOMETRY
148
● Light scattered by the particle is collected by detectors positioned at a variety of angles Around the capillary
● Cross-sectional area, and size or complexity/granularity of the particle
● Fluorescent molecules or fluorochromes may be attached to the particles and are excited by the incident light → fluorescent emission
FLOW CYTOMETRY
149
_________ at different angles - can
distinguish difference in size and internal
complexity
Light scattering
150
Light emitted from fluorescent labeled
particles or antibodies - can identify cell
surface and ?
cytoplasmic antigens
151
_________ cells express patterns of antigen
that are distinctly different from those of
their normal counterparts
Neoplastic
152
Which of the following karyotypes show euploidy?
a.46, XX
b.69,XXX
c.45,X
d.47,XX,+21
46,xx
153
The karyotype 46,XX,del(10)(q26.1q26.3) is an example of which chromosomal structural abnormality?
interstitial deletion
154
The cells are committed to advance further into the cell cycle after passing through which point in the cell cycle?
G1 RESTRICTION POINT
155
Which of the following structural chromosomal abnormalities result in significant loss of genetic information?
a.Balanced reciprocal translocation
b.Ring chromosome formation
c.Duplication
d. Inversion
RING CHROMOSOME
156
Nondysjunction occurring during the first meiotic division can give rise to which of the following zygotes?
a.Both of the given options
b.Normal
c.Neither of the given options
d.Trisomic
TRISOMIC
157
This is what we call to an individual if he/she is known to have symptoms of the disease or trait
AFFCTED INDIVIDUAL
158
The affected individual that brings the family to the attention of a geneticist is called:
PROBAND
159
- check for DNA damage
o If present, it will stop the cell cycle allow the cell to repair and continue the cell cycle
G1-S checkpoint
160
- check for damaged or unduplicated DNA
G2-M checkpoint
161
Which of the following is true in constitutional abnormality?
a.An acquired abnormality
b.Occurs late in the development
c.Seen in mosaicism
d.Found in all cells of the body
d.Found in all cells of the body
162
A mutation in the mitochondrial DNA may lead to the following diseases, EXCEPT:
A) MELAS
B) Encephalopathy
C) Myopathy
D) Renal cancer
d renal cancer
163
Alternative forms of genes are called
alleles
