PSIO 431 IMMUNO UAZ | QUESTIONS AND ANSWERS | 2026
UPDATE | WITH COMPLETE SOLUTION
A new species of rodent is found on a tiny island. Genetic analysis shows that it
is fully inbred. When its immunoglobulin genes are examined, its H chain
region shows 4 V, 3 D and 5 J segments. It has no lambda light chains, only
kappa; they have 5 V, and 3 J (there are no D regions in light chains). So,
ignoring any somatic mechanisms except V(D)J recombination, the germ line
alone predicts that this animal could make how many antibodies?
40
10,000
75
900 Answer - 900
Why is the quantity of IgE so low in the serum?
It binds immediately to Fc receptors on Mast cells
It is mostly found floating in the tissue fluids
It moves into the mucus membranes
It binds immediately to Fc receptors on neutrophils Answer - It binds
immediately to Fc receptors on Mast cells
Which class of antibody has a valence of 10?
IgE
IgM
,IgG
IgA Answer - IgM
My preparation of IgG anti-Streptococcus, which used to agglutinate the
bacteria very effectively, has been tampered with by my evil graduate student!
Now I find that what's in the tube binds specifically to Streptococcus, but there
is no agglutination! I think that what I have now is:
Fc
F(ab)2
Fab
Aged complement Answer - Fab
Lymphocytes are made to fit an antigen
Question 5 options:
True
False Answer - False
Scientists are developing a new herpes vaccine. They should focus on part of
the virus that is a good ___________.
Question 6 options:
Antigen
Mitogen
Epitope
Immunogen Answer - Antigen
Although _____is the most effective at activating complement, ___________is
the most abundant serum immunoglobulin.
Question 7 options:
,IgG; IgM
IgA; IgM
IgM; IgG
IgM; IgE Answer - IgM; IgG
I isolated a single plasma cell that was secreting IgG, and sequenced a single H
chain (new technology allows this with 100% accuracy). At the position in this
image shown by the arrow, on the Fc part of the H chain, I found the amino
acid serine. That was a surprise, as almost all humans have alanine at that
position. I asked an expert in my department what the amino acid in the exact
same position on the other H chain in this particular molecule would be. What
was the expert response?
There's no way to know based on the information above
Because of allotypic exclusion, it will be serine
Because of allotypic exclusion, it will be alanine
Statistically, it's much more likely to be alanine Answer - Because of allotypic
exclusion, it will be serine
Which of the following is the most sensitive test of antibody-antigen binding?
Question 9 options:
Precipitation
Hapten test
Lattice test
Agglutination Answer - Agglutination
Dr. Jenner showed that vaccination with Cowpox protected people from
Smallpox. What is that called?
Innoculation
Cross-Reaction
, Clonal Selection
Somatic Hypermutation Answer - Cross-Reaction
Got a 9/10 on these next 10 problems Answer -
A fetus makes both IgM and IgG antibodies
Question 1 options:
True
False Answer - False
I have a sample of cells from the bone marrow. What would be the first "sign"
that the cell I'm looking at is going to be a B cell?
Question 2 options:
cytoplasmic delta chain
cytoplasmic mu chain
surface IgM
surface IgD Answer - cytoplasmic mu chain
At birth an infant has 200 units of IgG antibody against rubella per ML in his
blood. He is not exposed to rubella. At 9 weeks of age, what should the
concentration be?
Question 3 options:
25 units
50 units
0 units, as he has not been exposed to the virus
100 units Answer - 25 units
UPDATE | WITH COMPLETE SOLUTION
A new species of rodent is found on a tiny island. Genetic analysis shows that it
is fully inbred. When its immunoglobulin genes are examined, its H chain
region shows 4 V, 3 D and 5 J segments. It has no lambda light chains, only
kappa; they have 5 V, and 3 J (there are no D regions in light chains). So,
ignoring any somatic mechanisms except V(D)J recombination, the germ line
alone predicts that this animal could make how many antibodies?
40
10,000
75
900 Answer - 900
Why is the quantity of IgE so low in the serum?
It binds immediately to Fc receptors on Mast cells
It is mostly found floating in the tissue fluids
It moves into the mucus membranes
It binds immediately to Fc receptors on neutrophils Answer - It binds
immediately to Fc receptors on Mast cells
Which class of antibody has a valence of 10?
IgE
IgM
,IgG
IgA Answer - IgM
My preparation of IgG anti-Streptococcus, which used to agglutinate the
bacteria very effectively, has been tampered with by my evil graduate student!
Now I find that what's in the tube binds specifically to Streptococcus, but there
is no agglutination! I think that what I have now is:
Fc
F(ab)2
Fab
Aged complement Answer - Fab
Lymphocytes are made to fit an antigen
Question 5 options:
True
False Answer - False
Scientists are developing a new herpes vaccine. They should focus on part of
the virus that is a good ___________.
Question 6 options:
Antigen
Mitogen
Epitope
Immunogen Answer - Antigen
Although _____is the most effective at activating complement, ___________is
the most abundant serum immunoglobulin.
Question 7 options:
,IgG; IgM
IgA; IgM
IgM; IgG
IgM; IgE Answer - IgM; IgG
I isolated a single plasma cell that was secreting IgG, and sequenced a single H
chain (new technology allows this with 100% accuracy). At the position in this
image shown by the arrow, on the Fc part of the H chain, I found the amino
acid serine. That was a surprise, as almost all humans have alanine at that
position. I asked an expert in my department what the amino acid in the exact
same position on the other H chain in this particular molecule would be. What
was the expert response?
There's no way to know based on the information above
Because of allotypic exclusion, it will be serine
Because of allotypic exclusion, it will be alanine
Statistically, it's much more likely to be alanine Answer - Because of allotypic
exclusion, it will be serine
Which of the following is the most sensitive test of antibody-antigen binding?
Question 9 options:
Precipitation
Hapten test
Lattice test
Agglutination Answer - Agglutination
Dr. Jenner showed that vaccination with Cowpox protected people from
Smallpox. What is that called?
Innoculation
Cross-Reaction
, Clonal Selection
Somatic Hypermutation Answer - Cross-Reaction
Got a 9/10 on these next 10 problems Answer -
A fetus makes both IgM and IgG antibodies
Question 1 options:
True
False Answer - False
I have a sample of cells from the bone marrow. What would be the first "sign"
that the cell I'm looking at is going to be a B cell?
Question 2 options:
cytoplasmic delta chain
cytoplasmic mu chain
surface IgM
surface IgD Answer - cytoplasmic mu chain
At birth an infant has 200 units of IgG antibody against rubella per ML in his
blood. He is not exposed to rubella. At 9 weeks of age, what should the
concentration be?
Question 3 options:
25 units
50 units
0 units, as he has not been exposed to the virus
100 units Answer - 25 units
