MIMG 185A Practice Midterm 2026 | Latest Update |
Questions & Answers | Graded A+
Question 1 (20 pts) A mother and child were recently rushed into a UCLA emergency room after
losing too much blood during a car accident. Both will need blood transfusions. Analysis of the
mother’s blood revealed the presence of antibodies with specificity for RBC antigens B and D. No
blood can be drawn from the child due to the large amount lost. This is NOT an only child or
adopted, but the youngest child according to the mother.
Note 1: Assume that for this question these existing antibody titers were low enough to not
influence the mother’s pregnancies.
Note 2: Each answer should be one sentence or less. Points will be deducted for answers longer
than one sentence. Show your work for full credit.
a) (4 pts) What are all possible full blood type(s) of the mother?
A-, O-
b) (4 pts) What donor blood type(s) can the mother receive safely?
A-, O-
c) (4 pts) The father makes it to the hospital. His blood is screened as AB+, what are all the
possible allelic combinations of the child? (note: assume for c-e that the father is
homozygous dominant for D, and the mother’s blood is not O type)
iA- x AB+ = iA+, iB+, AA+, AB+
AA- x AB+ = AA+, AB+, AA+, AB+
d) (4 pts) The hospital blood bank only has large quantities of B- blood available on short
notice for the child. What is the theoretical percent likelihood that the child survives the
blood transfusion?
Child could be A+ (4/8), B+ (1/8), AB+ (3/8)
Child will reject B- blood in 4/8=1/2 scenarios if A+, thus has a 50% chance of survival
e) (4 pts) Is B- blood a better option than the father donating blood to the child? Why or why
not?
Yes, father’s blood would lower survival to 3/8 from 4/8
, Ǫuestion 2 (25 pts) You perform a mouse parabiosis experiment using congenically
distinct CD45.1 and CD45.2 mice. You wait two weeks for the blood to reach chimerism
and when you examine the blood you see there is an equal contribution of the circulating
cells from one animal in the other. You harvest the liver of the CD45.1 mouse and examine
cell populations by flow cytometry.
a) Draw the expected flow plots for each cell type: (7pts)
Macrophage NK cell DC ILC1
B cell Naïve CD8 T ILC3
TR: Mac, DC, ILC1, ILC3,
Circulating: NK, B cell, Naïve CD8 T cell
In a subsequent experiment you infect two different mouse strains, Strain A and Strain B,
with parasite X and achieve the following data:
Strain A: 2/22 survive Strain B: 22/22 survive
b) Please list four potential defects of mouse strain A, with each defect
concerning/applying to a unique mechanism, pathway, or cell type (No explanation of
answers) (4pts)
1. TLR 2/6, MyD88
2. ILC2 / GATA3
3. cDC2
4. IgE/B cells or CD4 T cells
Questions & Answers | Graded A+
Question 1 (20 pts) A mother and child were recently rushed into a UCLA emergency room after
losing too much blood during a car accident. Both will need blood transfusions. Analysis of the
mother’s blood revealed the presence of antibodies with specificity for RBC antigens B and D. No
blood can be drawn from the child due to the large amount lost. This is NOT an only child or
adopted, but the youngest child according to the mother.
Note 1: Assume that for this question these existing antibody titers were low enough to not
influence the mother’s pregnancies.
Note 2: Each answer should be one sentence or less. Points will be deducted for answers longer
than one sentence. Show your work for full credit.
a) (4 pts) What are all possible full blood type(s) of the mother?
A-, O-
b) (4 pts) What donor blood type(s) can the mother receive safely?
A-, O-
c) (4 pts) The father makes it to the hospital. His blood is screened as AB+, what are all the
possible allelic combinations of the child? (note: assume for c-e that the father is
homozygous dominant for D, and the mother’s blood is not O type)
iA- x AB+ = iA+, iB+, AA+, AB+
AA- x AB+ = AA+, AB+, AA+, AB+
d) (4 pts) The hospital blood bank only has large quantities of B- blood available on short
notice for the child. What is the theoretical percent likelihood that the child survives the
blood transfusion?
Child could be A+ (4/8), B+ (1/8), AB+ (3/8)
Child will reject B- blood in 4/8=1/2 scenarios if A+, thus has a 50% chance of survival
e) (4 pts) Is B- blood a better option than the father donating blood to the child? Why or why
not?
Yes, father’s blood would lower survival to 3/8 from 4/8
, Ǫuestion 2 (25 pts) You perform a mouse parabiosis experiment using congenically
distinct CD45.1 and CD45.2 mice. You wait two weeks for the blood to reach chimerism
and when you examine the blood you see there is an equal contribution of the circulating
cells from one animal in the other. You harvest the liver of the CD45.1 mouse and examine
cell populations by flow cytometry.
a) Draw the expected flow plots for each cell type: (7pts)
Macrophage NK cell DC ILC1
B cell Naïve CD8 T ILC3
TR: Mac, DC, ILC1, ILC3,
Circulating: NK, B cell, Naïve CD8 T cell
In a subsequent experiment you infect two different mouse strains, Strain A and Strain B,
with parasite X and achieve the following data:
Strain A: 2/22 survive Strain B: 22/22 survive
b) Please list four potential defects of mouse strain A, with each defect
concerning/applying to a unique mechanism, pathway, or cell type (No explanation of
answers) (4pts)
1. TLR 2/6, MyD88
2. ILC2 / GATA3
3. cDC2
4. IgE/B cells or CD4 T cells
