Multiple Alleles and Immunogenetics

Question 1

T or F: The A and B alleles are codominant to each other and both are dominant to the O allele.

Answer 1

True

Question 2

Define codominance.

Answer 2

Have the same amount of dominance.

Question 3

Who can be the father of this child? Mom is blood type B. Baby is blood type A. John is type AB, Harry is type O, and Sam is type B. What is the genotype of the mother in this problem?

Answer 3

The mother has to be BO because she has to share the O with the baby. So that means that the father has to have an A, so it has to be John.

Question 4

Define: Antigen

Answer 4

A substance which stimulates production of an antibody.

Seen as “foreign”.

Question 5

Define: Antibody

Answer 5

A large Y-shape protein produced by plasma cells that is used by the immune system to identify and neutralize foreign objects such as bacteria and viruses.
Made in response to the entry of a foreign protein.
Coded for by genes.

Question 6

Define: Multiple alleles

Answer 6

More than 2 forms of the same gene.
Each person can still only have 2 alleles for the locus.
Involves more than just the typical two alleles that usually code for a certain characteristic.

Question 7

Define: Codominant

Answer 7

Describes genes that each have equal effect in making the character they control appear in offspring.

Question 8

The A and B proteins that are on the blood cells are (pick one: antigens or antibodies)

Answer 8

Antigens

Question 9

Which blood type is the Universal Donor? The Universal Recipient?

Answer 9

Universal Donor: O

Universal Recipient: AB

Question 10

Who can donate to Jane if Jane is Type A+?

Answer 10

AA, AO, OO

Question 11

Which of these loci contain multiple alleles? ABO Locus, HLA Locus, Rh Locus, Beta chain of Hemoglobin

Answer 11

Rh Locus

Question 12

What is RhoGAM? Who is it given to and under what conditions is it required?

Answer 12

RhoGAM is concentrated Rh+ antibodies. It is injected into mom within 72 hours after they deliver Rh+ baby. The antibodies destroy fetal Rh+ cells prior to mom making the antibodies.
A mother who is Rh- whose child is Rh+.

Question 13

RhoGAM is given to (Rh+ or Rh-) (mothers or babies) after the birth of an (Rh+ or Rh-) child.(Pick 1 in each set of parentheses)

Answer 13

Rh-
mothers
Rh+

Question 14

What does RhoGAM do?

Answer 14

RhoGAM antibodies destroy fetal Rh+ cells prior to mom making the antibodies.

Question 15

What does HLA stand for? Describe a situation when the alleles at the HLA loci are important medically.

Answer 15

Human Leukocyte Antigen
Coded for by 6 closely linked loci on Chr #6.
HLA-A, -B, -C, -DR, -DQ, -DP
Greater transplant success if match at HLA loci.

Question 16

Define: autograft

Answer 16

Taking from one place on the body and using for another place on the same body.
Genetically identical.

Question 17

Define: isograft

Answer 17

From an identical twin to the other identical twin.

Genetically identical, no risk of rejection.

Question 18

Define: allograft

Answer 18

Taken from and transplanted to the same species.

Question 19

Define: xenograft

Answer 19

Donor and recipient of transplant are of a different species.

Question 20

Define: haplotype

Answer 20

Array of HLA (Human Leukocyte Antigen) alleles on a given chr #6.

Question 21

What is organ trafficking? Discuss ethical issues associated with organ trafficking.

Answer 21

When a patient acquires a human organ from a donor illegally.
Illegal, unsafe, can cause more medical issues.

Question 22

What is transplant tourism? Discuss ethical issues involved with transplant tourism.

Answer 22

Patient (usually rich) travels to a foreign country to acquire human organ from (generally poverty stricken) donor outside legal jurisdiction.
Not legal, unsafe, can cause more medical issues.
Recipient may come back to the US in need of healthcare because of complications, and may use insurance policy. May also need another organ and be higher up on the organ donor list, even though they went and got one illegally and it didn’t work.

Question 23

What is the purpose of T cells? Where are they formed?

Answer 23

They fight infection.

T-cells mature in the thymus gland, in the small intestine, and the skin.

Question 24

What is the purpose of B cells? Where are they formed?

Answer 24

They secrete antibodies to fight infection or allergic reaction.
B-cells are released from lymphoid tissues, such as the spleen and lymph nodes.

Question 25

What is wrong in individuals with the following disorders? Diabetes (both types), Bruton’s Disease, SCID

Answer 25

Diabetes type I: Attacks cells in the pancreas that normally make insulin.
Diabetes type II: Degenerative, happens after 60 yrs.
Bruton’s Disease: Have T-cells, but no B cells, so no antibodies. (x-linked)
SCID: (Bubble boy) Missing T and B cells. 1 type is missing adenosine deaminase enzyme.

Question 26

What disorder did David (the Bubble Boy) have?

Answer 26

SCID