MCQ on Hemoglobin & Hemoglobinopathies

Multiple Choice Question of Hemoglobin and Hemoglobinopathies

1) Hemoglobin is a heme-containing globular protein present in erythrocytes. Which of the following is the function of hemoglobin
a) Storage of oxygen
b) Transport of oxygen
c) Both of the above
d) None of the above

2) Adult hemoglobin (HbA) is a tetrameter consisting of 
a) α2β2
b) α2δ2
c) α2γ2
d) β4

3) Which of the following is the oxygen binding site of the hemoglobin  
a) N-terminal of the beta subunit 
b) Carboxyterminal of both alpha and beta subunits
c) Ferric ion (Fe+3) of the heme molecule
d) Ferrous ion (Fe+2) of the heme molecule

4) Identify the correct statements regarding hemoglobin (HbA) from the following 
a) HbA shows hyperbolic oxygen dissociation curve 
b) HbA shows sigmoidal oxygen dissociation curve 
c) T-state favors the oxygen binding to hemoglobin
d) R-state favors the oxygen binding to hemoglobin

5) The following allosteric regulators favor the unloading of oxygen in the peripheral tissues 
a) Low pH
b) Low 2-3 Bisphosphoglycerate
c) Low partial pressure of carbon dioxide
d) All of the above

6) Carbononooxide poisoning decreases oxygen delivery and causes tissue hypoxia and may lead to death in untreated individuals. The carbon monoxide 
a) Bind to the N-terminal chain and decreases the affinity of oxygen to a heme 
b) Competitively binds to oxygen binding site of hemoglobin at higher affinity 
c) Competitively Interfere with the binding of 2,3 BPG to hemoglobin
d) All of the above

Hemoglobinopathies 
7) Hydrops fetalis is a clinical condition caused by the deletion of the alpha genes of hemoglobin. Among a total of four alpha genes, the  hydrops fetalis is caused by deletion of 
a)  One alpha gene
b) Two alpha gene
c) Three alpha gene 
d) Four alpha gene

8) Hemoglobin H disease is characterized by the deletion of 
a)  One alpha gene
b) Two alpha gene
c) Three alpha gene 
d) Four alpha gene

9) beta-thalassemia minor is characterized by 
a) Defective mutation of one of two beta genes of hemoglobin
b) Increased Hemoglobin A2
c) Increased Hemoglobin F
d) All of the above
e) None of the above

10) Sideroblastic anemia is a disorder in which the body has adequate iron stores, but unable to incorporate the iron into hemoglobin. Which of the following is not the characteristic feature of sideroblastic anemia 
a) Increased Serum Iron
b) Increased Ferritin
c) Increased TIBC
d) Increased % Saturation of TIBC

11) Sickle cell disease is an inherited blood disorder of hemoglobin synthesis. Identify the correct answer from the following
a) caused by a mutation in the sixth position of alpha chain (glutamic acid is replaced by isoleucine)
b) caused by a mutation in the sixth position of beta chain (glutamic acid is replaced by isoleucine)
c) caused by a mutation in the sixth position of alpha chain (glutamic acid is replaced by valine)
d) caused by a mutation in the sixth position of beta chain (glutamic acid is replaced by valine)

12) Which of the following conditions worsen symptoms associated with sickle cell disease
a) Decrease pH associated with exercise
b) Increase fetal hemoglobin
c) Increased hemoglobin C
d) All of the above 
e) None of the above

13) Hemoglobin C disease occurs when a single nucleotide change in a codon causes
lysine (basic) to replace normal glutamic acid (acidic) at the beta 6 positions.
Hemoglobin C disease is characterized by 
a) Mild normochromic-normocytic anemia,
b) Splenomegaly, 
c) Rod-shaped crystals in erythrocytes
d) All of the above
c) None of the above

14) Which of the following is the classical symptoms of sickle cell anemia
a) Severe hemolytic anemia caused by increase erythrocyte destruction
b) Increased hyperbilirubinemia
c) Vasso-occlusive crisis
d) All of the above
e) None of the above

15) In patients with sickle cell disease, sickling of RBC is favorable when hemoglobin S is 
a) Oxygenated Form
b) Deoxygenated Form
c) Glycated Form
d) All of the above
e) None of the above
.............................................................

Answers Key MCQ Hemoglobin & Hemoglobinopathies 

1)- b) Transport of oxygen
2)- a) α2β2
3)- d) Ferrous ion (Fe+2) of the heme molecule
4)- a) & d)
5)-a) Low pH
6- b) Competitively binds to oxygen binding site of hemoglobin at higher affinity 
7-d) Four alpha gene
8-c) Three alpha gene 
9-d) All of the above
10-c) Increased TIBC
11-d) caused by a mutation in the sixth position of beta chain (glutamic acid is replaced by valine)
12-a) Decrease pH associated with exercise
13-d) All of the above
14d) All of the above
15-b) Deoxygenated


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