Exam 3: BIOS252/ BIOS 252 (New 2025/ 2026 Update) Anatomy and Physiology
II Guide| Qs & As| Grade A| 100% Correct (Verified Answers)- Chamberlain
Question 1
Which of the following is the most abundant plasma protein and is primarily responsible for
maintaining colloid osmotic pressure?
A) Fibrinogen
B) Gamma globulin
C) Albumin
D) Prothrombin
E) Hemoglobin
Correct Answer: C) Albumin
Rationale: Albumin is produced by the liver and makes up about 60% of plasma proteins.
Its large size and abundance allow it to pull water into the capillaries via osmosis,
preventing edema and maintaining blood volume and pressure.
Question 2
A patient with Type A+ blood can safely receive a transfusion from which of the following
donors?
A) Type B+
B) Type AB+
C) Type O-
D) Type AB-
E) Type B-
Correct Answer: C) Type O-
Rationale: Type O- is the universal donor because it lacks A, B, and Rh antigens, meaning
the recipient's antibodies will not attack the infused cells. A Type A+ patient has anti-B
antibodies and cannot receive B or AB blood.
Question 3
Which leukocyte is the first to arrive at the site of an acute bacterial infection and performs
phagocytosis?
A) Basophil
B) Eosinophil
C) Monocyte
D) Neutrophil
E) Lymphocyte
Correct Answer: D) Neutrophil
Rationale: Neutrophils are the most numerous WBCs (50-70%) and act as the "first
responders" to bacterial invasion. They utilize chemotaxis to locate bacteria and destroy
them through phagocytosis and respiratory bursts.
Question 4
Which stage of hemostasis involves the conversion of soluble fibrinogen into insoluble fibrin
, 2
strands?
A) Vascular spasm
B) Platelet plug formation
C) Coagulation
D) Clot retraction
E) Thrombolysis
Correct Answer: C) Coagulation
Rationale: Coagulation is the third stage of hemostasis. It involves a complex cascade of
clotting factors ending in the activation of thrombin, which catalyzes the transformation of
fibrinogen into a fibrin mesh that traps blood cells.
Question 5
Erythropoietin (EPO) is a hormone released by the ________ in response to ________.
A) Liver; high blood pressure
B) Kidneys; low blood oxygen (hypoxia)
C) Bone marrow; high iron levels
D) Spleen; bacterial infection
E) Pancreas; low blood glucose
Correct Answer: B) Kidneys; low blood oxygen (hypoxia)
Rationale: When oxygen levels drop, specialized cells in the kidneys detect the hypoxia and
release EPO. EPO then travels to the red bone marrow to stimulate the production of new
erythrocytes (erythropoiesis).
Question 6
Which component of the hemoglobin molecule specifically binds to oxygen?
A) The globin protein chains
B) The iron ion in the center of the heme group
C) The amino acid sequences of the beta chains
D) The biliverdin pigment
E) The plasma membrane of the RBC
Correct Answer: B) The iron ion in the center of the heme group
Rationale: Each hemoglobin molecule contains four heme groups, each with an iron atom (
𝐹𝑒 2+
) at its center. Oxygen binds reversibly to this iron atom, allowing for transport from the
lungs to the tissues.
Question 7
During a CBC, a patient is found to have an elevated eosinophil count (eosinophilia). Which
condition is most likely?
A) Acute appendicitis
, 3
B) Iron deficiency anemia
C) Parasitic worm infection
D) Myocardial infarction
E) Viral influenza
Correct Answer: C) Parasitic worm infection
Rationale: Eosinophils are specialized for attacking parasites (like helminths) by releasing
cytotoxic enzymes. They also play a role in modulating allergic reactions.
Question 8
What is the correct sequence of the heart’s electrical conduction system?
A) AV node
→
SA node
→
Purkinje fibers
→
AV bundle
B) SA node
→
AV node
→
AV bundle
→
Bundle branches
→
Purkinje fibers
C) SA node
→
AV bundle
→
Purkinje fibers
, 4
→
AV node
D) Purkinje fibers
→
Bundle branches
→
AV node
→
SA node
E) AV bundle
→
AV node
→
SA node
→
Purkinje fibers
Correct Answer: B) SA node
→
AV node
→
AV bundle
→
Bundle branches
→
Purkinje fibers
Rationale: The SA node acts as the primary pacemaker. The impulse travels through the
atria to the AV node (where it pauses), then down the AV bundle (Bundle of His), into the
right and left bundle branches, and finally to the Purkinje fibers to trigger ventricular
contraction.
II Guide| Qs & As| Grade A| 100% Correct (Verified Answers)- Chamberlain
Question 1
Which of the following is the most abundant plasma protein and is primarily responsible for
maintaining colloid osmotic pressure?
A) Fibrinogen
B) Gamma globulin
C) Albumin
D) Prothrombin
E) Hemoglobin
Correct Answer: C) Albumin
Rationale: Albumin is produced by the liver and makes up about 60% of plasma proteins.
Its large size and abundance allow it to pull water into the capillaries via osmosis,
preventing edema and maintaining blood volume and pressure.
Question 2
A patient with Type A+ blood can safely receive a transfusion from which of the following
donors?
A) Type B+
B) Type AB+
C) Type O-
D) Type AB-
E) Type B-
Correct Answer: C) Type O-
Rationale: Type O- is the universal donor because it lacks A, B, and Rh antigens, meaning
the recipient's antibodies will not attack the infused cells. A Type A+ patient has anti-B
antibodies and cannot receive B or AB blood.
Question 3
Which leukocyte is the first to arrive at the site of an acute bacterial infection and performs
phagocytosis?
A) Basophil
B) Eosinophil
C) Monocyte
D) Neutrophil
E) Lymphocyte
Correct Answer: D) Neutrophil
Rationale: Neutrophils are the most numerous WBCs (50-70%) and act as the "first
responders" to bacterial invasion. They utilize chemotaxis to locate bacteria and destroy
them through phagocytosis and respiratory bursts.
Question 4
Which stage of hemostasis involves the conversion of soluble fibrinogen into insoluble fibrin
, 2
strands?
A) Vascular spasm
B) Platelet plug formation
C) Coagulation
D) Clot retraction
E) Thrombolysis
Correct Answer: C) Coagulation
Rationale: Coagulation is the third stage of hemostasis. It involves a complex cascade of
clotting factors ending in the activation of thrombin, which catalyzes the transformation of
fibrinogen into a fibrin mesh that traps blood cells.
Question 5
Erythropoietin (EPO) is a hormone released by the ________ in response to ________.
A) Liver; high blood pressure
B) Kidneys; low blood oxygen (hypoxia)
C) Bone marrow; high iron levels
D) Spleen; bacterial infection
E) Pancreas; low blood glucose
Correct Answer: B) Kidneys; low blood oxygen (hypoxia)
Rationale: When oxygen levels drop, specialized cells in the kidneys detect the hypoxia and
release EPO. EPO then travels to the red bone marrow to stimulate the production of new
erythrocytes (erythropoiesis).
Question 6
Which component of the hemoglobin molecule specifically binds to oxygen?
A) The globin protein chains
B) The iron ion in the center of the heme group
C) The amino acid sequences of the beta chains
D) The biliverdin pigment
E) The plasma membrane of the RBC
Correct Answer: B) The iron ion in the center of the heme group
Rationale: Each hemoglobin molecule contains four heme groups, each with an iron atom (
𝐹𝑒 2+
) at its center. Oxygen binds reversibly to this iron atom, allowing for transport from the
lungs to the tissues.
Question 7
During a CBC, a patient is found to have an elevated eosinophil count (eosinophilia). Which
condition is most likely?
A) Acute appendicitis
, 3
B) Iron deficiency anemia
C) Parasitic worm infection
D) Myocardial infarction
E) Viral influenza
Correct Answer: C) Parasitic worm infection
Rationale: Eosinophils are specialized for attacking parasites (like helminths) by releasing
cytotoxic enzymes. They also play a role in modulating allergic reactions.
Question 8
What is the correct sequence of the heart’s electrical conduction system?
A) AV node
→
SA node
→
Purkinje fibers
→
AV bundle
B) SA node
→
AV node
→
AV bundle
→
Bundle branches
→
Purkinje fibers
C) SA node
→
AV bundle
→
Purkinje fibers
, 4
→
AV node
D) Purkinje fibers
→
Bundle branches
→
AV node
→
SA node
E) AV bundle
→
AV node
→
SA node
→
Purkinje fibers
Correct Answer: B) SA node
→
AV node
→
AV bundle
→
Bundle branches
→
Purkinje fibers
Rationale: The SA node acts as the primary pacemaker. The impulse travels through the
atria to the AV node (where it pauses), then down the AV bundle (Bundle of His), into the
right and left bundle branches, and finally to the Purkinje fibers to trigger ventricular
contraction.
