Exam 3 Flashcards
(121 cards)
1
Q
Locus
A
location of the gene on chromosome
2
Q
Allele
A
one of two or more different genes that my occupy a specific locus on a chromosome
3
Q
homozygous
A
having two identical alleles for a given gene
4
Q
heterozygous
A
having two different alleles for a given gene
5
Q
dominant
A
a gene that is always expressed whether it is present in the homo or heterozygous state
6
Q
recessive
A
a gene that is expressed only when it is in the homozygous state
7
Q
Co-dominant/ Egalitarian
A
both alleles are expressed in the heterozygous state (AB blood)
8
Q
amorph or silent allele
A
a gene that produces no product even in the homozygous state
9
Q
phenotype
A
the detectable products of genes only discovered through the description of observed traits or the result of direct testing (Ph-physical trait)
10
Q
genotype
A
total sum of genes present on the chromosomes with the respect to the one or more characteristics, regardless of whether or not they produce detectable products
11
Q
Zeta Potential
A
decrease in the electrical charge of RBC when it is suspended in a high ionic strength colloidal medium (albumin) also decreases the repulsion of the RBCs
12
Q
What is the “job” of IgG and IgM in terms of bridging the gap between RBCs?
A
IgM bridges the gap easier because they are larger than IgG
13
Q
What is the temp reactivity of IgG and IgM?
A
IgG reacts at 30-37°C and IgM at 4-27°C
14
Q
What is the effect of LISS in the Ag-Ab reaction?
A
The addition of LISS will help the rate of association between antigen and antibody. The rate is increased by lowering the ionic strength.
15
Q
4 enzymes used in the blood bank
A
ficin papain trypsin bromelin
16
Q
AHG effects and what does it do?
A
useful in detecting IgG and complement
17
Q
What is dosage?
A
homozygous gives stronger reactions than heterozygous
- also is a word that describes a significant difference in antibody reaction strength depending on the amount of corresponding antigen present on a reb blood cell. The difference in antigen quantity is determind by the zygosity of the gene coding for the antigen
18
Q
T/F Lewis antibodies commonly cause HDN and HTR.
A
False - they can not cross the placenta and they will convert in a transfusion.
19
Q
What is the genotype and phenotypes of Bombay?
A
Oh - phenotype hh - genotype
20
Q
Which precursor type substance for ABH antigens?
A
Type 2
21
Q
Name the two stages of RBC agglutination in correct order of sequence.
A
- sensitization 2. clumping (agglutination)
22
Q
The reverse or backside test detects the presence or absence of..
A
Ab using the patient’s serum/plasma Ag using RBC
23
Q
The forward test detects..
A
antigens in the patient’s RBC using antisera.
24
Q
Does Lewis cause HDN? Why?
A
No, because it cannot cross the placenta and because it is not fully developed in a newborn.
25
What antibodies most often cause HDN?
Rh
26
What are you called if you have no Rh antigens?
Rh null
27
T/F Lewis antibodies are enhanced by enzymes.
True
28
T/F Lewis antigens tend to become stronger during pregnancy.
False - they become weaker.
29
T/F Lewis antibodies usually occur without known RBC stimulus.
True
30
T/F The Lewis system includes soluble antigens that are present in saliva and plasma with antigenic determinants occurring naturally on the RBC surface.
False - they are made in the tissue and are not on the RBC surface.
31
T/F The Rh system was the first to be discovered and by far the most significant for transfusion practice.
False - the ABO was the first to be discovered and is most significant for transfusion.
32
T/F Rh Abs react more strongly at 4°C than at 37°C.
False - IgG likes 37°.
33
T/F Rh Abs can cross the placenta.
True.
34
T/F Rh Abs are not a frequent cause of HDN.
False
35
Where would we find anti-A1?
A 2 B A 3 A x A 2
36
Where would you see mixed field agglutination with Anti-A..?
A3
37
What % of Caucasians are secretors?
80%
38
Where would you find anti-AB antiserum?
O blood type
39
Anti-C antiserum will react with an individual with type..?
R1 R2 (DCe/DcE) r ry (dce/dCE) r' r'' (dCe/dcE) Rz r (DCE/dce) any ""C""
40
When would you do a weak D testing?
if the initial spin is negative for a donor.
41
What would be a good indication of HDN testing?
Serum Bilirubin DAT - (if + do an elution and antibody ID) Cord blood Hemoglobin
42
What is dolichos biflorus?
An anti-A1 lectin used to confirm the antigens on RBCs.
43
Who is a good candidate for Rho-gam?
Rh-negative mothers who deliver Rh-positive babies.
44
List the H substance demonstrated in order of decreasing reactivity.
O\>A2\>B\>A2B\>A1\>A1B
45
What is Landsteiner's Rule?
Ab are present in plasma only when the corresponding Ag is not present on the RBCs.
46
Why are cord cells washed?
To remove Wharton's jelly.
47
Secretor status test used for H substance
inhibition and neutralization tests
48
Why is Anti-AB antiserum used in the lab?
Detection of subgroups of A weaker than A2
49
If you have two parents that are A1/A1 and A1/A2, what is the phenotype of their offspring?
A
50
If you have MM and MN, which agglutinates more strongly? Why?
MM, due to the dosage effect. It affects more strongly in the homozygous state.
51
Will time have an effect on an antigen/antibody reaction?
Yes
52
Will overcentrifugation cause a false negative in an antigen/antibody reaction?
No - it is more likely to give a false positive.
53
Is a reaction at 4°C clinically significant?
No.
54
If you decrease serum:cell ratio, does it provide more antibody molecules to the antigen sites available for reaction?
No
55
Are Lewis antibodies clinically significant?
No
56
Can nonsecretors secrete ABO substances regardless of ABO group?
No
57
What is the Rh negative genotype?
dd
58
For Rh antibodies, which is true? -React better at 37°C then 4°C -Cross the placenta -Frequently cause HDN
All are true
59
Do some A2 individuals produce Anti-A1?
Yes - 8%
60
If you had the following blood types, which would react with Anti-C? Dce dce DcE/DcE dCe
dCe
61
Where does anti-AB antisera come from?
Humans with type O blood.
62
Which is least useful for studying HDN? -Elution & Antibody ID -Serum bilirubin -Direct antiglobulin -Cord blood hemoglobin -Secretor testing
Secretor testing.
63
What is the purpose of Rh immune globulin?
To prevent sensitization of the Rh negative mother to the baby's Rh positive blood.
64
To truly designate Rh negative:
Blood will not react with Anti-D Proceed to Weak D testing
65
Which would be useful in detecting secretor status for H substance? 1. A1 lectin 2. Boiled saliva 3. Ulex europaeus extract 4. A cells 5. O cells
1. No 2. Yes 3. Yes 4. No 5. Yes Why O cells? Increased H antigen sites.
66
If a mother is D- and Dw- and a father is homozygous for D antigen, what will their offspring's genotype be?
100% Dd+
67
What causes HDN to occur?
Maternal cells lack antigen that fetal cells have. That's what causes sensitization.
68
Reverse ABO grouping is inadequate in..
newborns
69
Name the antisera used in detecting Rh.
Anti-D Anti-C Anti-E Anti-c Anti-e
70
Another name for F antigen is
compound antigen
71
What is present when F antigen is expressed on RBCs?
c & e inherited on the same haplotype.
72
Which will react with Anti-F? DCe DcE Dce dCe dcE Dce
Dce
73
With R1R1 individuals (DCe/DCe), if given dce, what antibody will most likely form?
Anti-c
74
Which blood group reacts most strongly with Anti-H lectin (Ulex europaeus)?
Group O
75
The ____________ is the total sum of genes present on the chromosomes with respect to one of more characteristics, regardless of whether or not they produce detectable products.
Genotype
76
A ______ gene is always expressed whether it is present in the homozygous or heterozygous state.
Dominant
77
A _______ is a gene that produces no product even in the homozygous state.
Amorph
78
A ________ gene is expressed only when it is in the homozygous state.
Recessive
79
The ______ is the detectable products of genes only discovered through a description of observed traits or the result of direct testing.
Phenotype
80
Name two substances that can reduce the zeta potential and allow red blood cells to approach each other more closely and be agglutinated.
Albumin and LISS
81
Name two other influencing factors in Ag-Ab reactions.
Ag- temperature, pH, centrifugation, amount of time,
Ab- concentration, ionic strength, dosage
82
The _____ gene is necessary for the expression of the ABO genes.
H
83
Ulex europeaus is a lectin with _______ specificity, whereas Dolichos biflorus is a lectin with ______ specificity.
Anti-H and Anti-A
84
List the three genotypes that produce the A1 phenotype.
A1A1, A1A2, A1O
85
List the possible genotypes and phenotypes from a mating of AB and BO individuals.
Genotypes: A2B Phenotypes: A1, A2, B1A1, A2B, O
86
Individuals that do not inherit the H gene have the genotype ____ and are said to have the \_\_\_\_\_phenotype; they also possess and additional Ab, \_\_\_\_\_\_\_\_, in comparison to normal O individuals.
hh, Bombay, Anti-H
87
Lewis antibodies usually occur without known RBC stimulus.
True
88
Lewis antibodies commonly cause HDN and HTR.
False, Lewis Ab decrease in pregnancy
89
Give one reason why Lewis antibodies do not cause HDN.
B/C the Lea and Leb Ag are not well developed at birth. Anti Lea and anti-Leb are IgM and cannot cross placenta.
90
r
dce
91
r'
dCe
92
r"
dcE
93
ry
dCE
94
R'
DCe
95
R"
DcE
96
R0(zero)
Dce
97
Rz
DCE
98
Rh genes in order of frequency in Caucasians:
- Most freq: R'-DCe
- 2nd most freq: r-dce
- 3rd most freq: R''-DcE
- least freq- ry-dCE
99
The gene complex which could produce a RBC Ag that reacts with anti-f has both ____ and ____ on the same gene.
c and e
100
A Rh negative individual has the genotype \_\_\_\_\_.
dd
101
State the phenotype of the children of a negative mother who is homozygous for the D ag and a father who is D negative D (weak pos) negative.
All D- Rh +
102
What test need to be done and what are the results of the test for a donor to be designated as Rh negative.
Weak D Test
103
Anti-C antiserum will react with the following RBCs.
R' R'' r ry r' r" Rz
104
the Rh system was the first to be discovered and by far the most significant for transfusion practice
FALSE
105
The Rh Abs can cross the placenta.
True
106
Rh Abs are not a freq cause of HDN
False; ABO and Rh are the most common cause
107
Good indication of HDN(testing wise)?
Bilirubin, DAT(elution and Ab testing), hemoglobin
108
AHG
Anti-Human Globulin- antisera that contains Ab Coombs test-
109
Anti-A1
Found naturally occurring in IgM Ab produced by some subgroups of A. Prepared from seeds of plant Dolichos biflorus
110
Rh Ab characteristics
Well develop[ed at birth so one of the main causes of HDN; Very good immunogens; D most immunogenic after A and B; fewer Ag sites then ABO; not soluble and not expressed on tissues
111
location of the gene on chromosome
Locus
112
one of two or more different genes that my occupy a specific locus on a chromosome
Allele
113
having two identical alleles for a given gene
homozygous
114
having two different alleles for a given gene
heterozygous
115
a gene that is always expressed whether it is present in the homo or heterozygous state
dominant
116
a gene that is expressed only when it is in the homozygous state
recessive
117
both alleles are expressed in the heterozygous state (AB blood)
Co-dominant/ Egalitarian
118
a gene that produces no product even in the homozygous state
amorph or silent allele
119
the detectable products of genes only discovered through the description of observed traits or the result of direct testing (Ph-physical trait)
phenotype
120
total sum of genes present on the chromosomes with the respect to the one or more characteristics, regardless of whether or not they produce detectable products
genotype
121
decrease in the electrical charge of RBC when it is suspended in a high ionic strength colloidal medium (albumin) also decreases the repulsion of the RBCs
Zeta Potential
