SBB ASCP COMPREHENSIVE EXAM 2026
QUESTIONS WITH SOLUTIONS GRADED A+
◉ If anti-K reacts 3+ with a donor cell with a
genotype KK and 2+ with a Kk cell, the antibody
is demonstrating: Answer: Dosage
◉ Carla expresses the blood group antigens Fya, Fyb, and Xga. James
shows expressions of none of these antigens. What factor(s) may
account for the absence of these antigens in James? Answer: Gender and
Race. The frequency of Duffy antigens Fya and Fyb varies
with race. The Fy(a−b−) phenotype occurs in almost
70% of African Americans and is very rare in whites.
The Xga antigen is X-linked and, therefore, expressed more frequently
in women (who may inherit the antigen from either parent) than in men.
◉ Which of the following statements is true?
A. An individual with the BO genotype is
homozygous for B antigen
B. An individual with the BB genotype is
homozygous for B antigen
C. An individual with the OO genotype is
,heterozygous for O antigen
D. An individual with the AB phenotype is
homozygous for A and B antigens Answer: B. An individual with the BB
genotype is
homozygous for B antigen
◉ Which genotype is heterozygous for C?
A. DCe/dce
B. DCE/DCE
C. Dce/dce
D. DCE/dCe Answer: A. DCe/dce
◉ Which genotype(s) will give rise to the Bombay phenotype? Answer:
The Bombay phenotype will be expressed only when no H substance is
present. The Oh type is expressed by the genotype hh. Bombays produce
naturally occurring anti-H, and their serum agglutinates group
O red cells in addition to red cells from groups A, B, and AB persons.
◉ Meiosis in cell division is limited to the ova and sperm producing four
gametes containing what complement of DNA? Answer: 1N. Meiosis
involves two nuclear divisions in succession resulting in four
gametocytes each containing half the number of chromosomes found in
somatic cells or 1N.
,◉ A cell that is not actively dividing is said to be in: Answer: Interphase,
The cell is engaged in metabolic activity. Chromosomes are not clearly
discerned; however, nucleoli may be
visible
◉ Which of the following describes the expression of most blood group
antigens? Answer: Codominant
◉ What blood type is not possible for an offspring of an AO and BO
mating? Answer: All are possible
◉ The alleged father of a child in a disputed case of paternity is blood
group AB. The mother is group O and the child is group O. What type of
exclusion is this? Answer: -Indirect/secondary/second order
An indirect/secondary/second order exclusion occurs when a genetic
marker is absent in the child but should have been transmitted by the
alleged father. In this case, either A or B should be present in the child.
◉ If the frequency of gene Y is 0.4 and the frequency of gene Z is 0.5,
one would expect that they should occur together 0.2 (20%) of the time.
In actuality,
they are found together 32% of the time. This is an example of: Answer:
Linkage disequilibrium.
, Linkage disequilibrium is a phenomenon in which alleles situated in
close proximity on a chromosome associate with one another more than
would be expected from individual allelic frequencies.
◉ In this type of inheritance, the father carries the trait on his X
chromosome. He has no sons with the trait because he passed his Y
chromosome to his sons; however, all his daughters will express the
trait. Answer: Autosomal Dominant
◉ In the Hardy-Weinberg formula, p2 represents: Answer: In the Hardy-
Weinberg formula p2 + 2pq + q2, p2 and q2 represent homozygous
expressions and 2pq represents heterozygous expression. This formula is
used in population genetics to determine the frequency of different
alleles.
◉ What is the Hardy-Weinberg formula? Answer: p2 + 2pq + q2 = 1
◉ Why do IgM antibodies, such as those formed against the ABO
antigens, have the ability to directly agglutinate red blood cells (RBCs)
and cause visible agglutination? Answer: IgM antibodies are larger
molecules and have the ability to bind more antigen
◉ Which of the following enhancement mediums decreases the zeta
potential, allowing antibody and antigen to come closer together?
Answer: LISS.
QUESTIONS WITH SOLUTIONS GRADED A+
◉ If anti-K reacts 3+ with a donor cell with a
genotype KK and 2+ with a Kk cell, the antibody
is demonstrating: Answer: Dosage
◉ Carla expresses the blood group antigens Fya, Fyb, and Xga. James
shows expressions of none of these antigens. What factor(s) may
account for the absence of these antigens in James? Answer: Gender and
Race. The frequency of Duffy antigens Fya and Fyb varies
with race. The Fy(a−b−) phenotype occurs in almost
70% of African Americans and is very rare in whites.
The Xga antigen is X-linked and, therefore, expressed more frequently
in women (who may inherit the antigen from either parent) than in men.
◉ Which of the following statements is true?
A. An individual with the BO genotype is
homozygous for B antigen
B. An individual with the BB genotype is
homozygous for B antigen
C. An individual with the OO genotype is
,heterozygous for O antigen
D. An individual with the AB phenotype is
homozygous for A and B antigens Answer: B. An individual with the BB
genotype is
homozygous for B antigen
◉ Which genotype is heterozygous for C?
A. DCe/dce
B. DCE/DCE
C. Dce/dce
D. DCE/dCe Answer: A. DCe/dce
◉ Which genotype(s) will give rise to the Bombay phenotype? Answer:
The Bombay phenotype will be expressed only when no H substance is
present. The Oh type is expressed by the genotype hh. Bombays produce
naturally occurring anti-H, and their serum agglutinates group
O red cells in addition to red cells from groups A, B, and AB persons.
◉ Meiosis in cell division is limited to the ova and sperm producing four
gametes containing what complement of DNA? Answer: 1N. Meiosis
involves two nuclear divisions in succession resulting in four
gametocytes each containing half the number of chromosomes found in
somatic cells or 1N.
,◉ A cell that is not actively dividing is said to be in: Answer: Interphase,
The cell is engaged in metabolic activity. Chromosomes are not clearly
discerned; however, nucleoli may be
visible
◉ Which of the following describes the expression of most blood group
antigens? Answer: Codominant
◉ What blood type is not possible for an offspring of an AO and BO
mating? Answer: All are possible
◉ The alleged father of a child in a disputed case of paternity is blood
group AB. The mother is group O and the child is group O. What type of
exclusion is this? Answer: -Indirect/secondary/second order
An indirect/secondary/second order exclusion occurs when a genetic
marker is absent in the child but should have been transmitted by the
alleged father. In this case, either A or B should be present in the child.
◉ If the frequency of gene Y is 0.4 and the frequency of gene Z is 0.5,
one would expect that they should occur together 0.2 (20%) of the time.
In actuality,
they are found together 32% of the time. This is an example of: Answer:
Linkage disequilibrium.
, Linkage disequilibrium is a phenomenon in which alleles situated in
close proximity on a chromosome associate with one another more than
would be expected from individual allelic frequencies.
◉ In this type of inheritance, the father carries the trait on his X
chromosome. He has no sons with the trait because he passed his Y
chromosome to his sons; however, all his daughters will express the
trait. Answer: Autosomal Dominant
◉ In the Hardy-Weinberg formula, p2 represents: Answer: In the Hardy-
Weinberg formula p2 + 2pq + q2, p2 and q2 represent homozygous
expressions and 2pq represents heterozygous expression. This formula is
used in population genetics to determine the frequency of different
alleles.
◉ What is the Hardy-Weinberg formula? Answer: p2 + 2pq + q2 = 1
◉ Why do IgM antibodies, such as those formed against the ABO
antigens, have the ability to directly agglutinate red blood cells (RBCs)
and cause visible agglutination? Answer: IgM antibodies are larger
molecules and have the ability to bind more antigen
◉ Which of the following enhancement mediums decreases the zeta
potential, allowing antibody and antigen to come closer together?
Answer: LISS.
