60 free Blood Types trivia questions with answers — science & nature quiz, new questions added Aug 2026.
This blood types trivia quiz covers everything from the four ABO groups you learned at school to the 48 blood group systems that transfusion scientists actually track. It starts with the basics (which group is the universal donor, which is the universal recipient, what the + and - stand for), then follows the history: Karl Landsteiner's clumping test tubes in 1901, the confusing rival numbering schemes, the rabbit-and-macaque experiment behind the Rh factor, and the first blood bank in Chicago. From there it heads into the rare and strange: golden blood, the Bombay phenotype, why Duffy-negative blood protects against malaria, which soldiers had their group tattooed on, how a bone marrow transplant can change your type, and why Japanese employers and matchmakers ask about blood type at all. About a third of the questions are easy enough for a biology class; the rest are for nurses, lab scientists and quiz obsessives. Our broader blood trivia quiz covers cells, circulation and haemophilia. Every answer was checked against Wikipedia's articles on blood types, the ABO and Rh systems, transfusion and blood donation, and each explanation adds one more detail.
30 of 60 questions with answers and explanations. Play the quiz
Q 01Blood types are defined by antigens on the surface of what?
Red cells
The antigens can be proteins, carbohydrates, glycoproteins or glycolipids depending on the blood group system.
Q 02Which two blood group systems matter most when matching blood for a transfusion?
ABO and Rh
Together they give the familiar labels such as A+, O- or AB+.
Q 03How many human blood group systems did the ISBT recognise as of 2025?
48
A truly complete blood type would describe a person's status in every one of the 48 systems recognised by 2025.
Q 04Which blood group has neither the A nor the B antigen on its red cells?
O
Its plasma carries both anti-A and anti-B antibodies, which is why it can only receive from its own group.
Q 05People with which ABO group are known as 'universal recipients' for red cells?
AB
Their plasma has no anti-A or anti-B antibodies, so red cells from any group are tolerated, but they can only donate to their own group.
Q 06Which blood type is called the 'universal donor' for red cell transfusions?
O negative
Because it can go to anyone in an emergency, it is often overused and almost always in short supply.
Q 07What kind of antibodies are the naturally occurring anti-A and anti-B in human plasma?
IgM
They are thought to develop in the first years of life through exposure to food, bacteria and viruses.
Q 08What letter did the discoverer of the ABO groups originally use for the group now called O?
C
His 1901 scheme was A, B and C; the C was later replaced by O.
Q 09The letter O in the ABO system was chosen to stand for a German word meaning what?
Without
Some scientists preferred the numeral zero, and in many languages the group is still called 0.
Q 10Which group was discovered a year after the first three, by his students Sturli and von Decastello?
AB
They did not even give it a name at first, calling it 'no particular type'.
Q 11In which year did Karl Landsteiner make his definitive observation of blood-group agglutination?
1901
He had noticed the clumping (agglutination) the year before, even between human and animal blood.
Q 12The discoverer of blood groups won the Nobel Prize in Physiology or Medicine in which year?
1930
He had by then emigrated to New York to work at the Rockefeller Institute.
Q 13Besides blood groups, the discoverer of the ABO system co-discovered which virus in 1909?
Polio
He worked with Constantin Levaditi and Erwin Popper on the discovery.
Q 14World Blood Donor Day, held on 14 June, marks the birthday of whom?
Q 21Which Rh antigen is the most important, because it most often provokes an immune response?
D
The + or - after your ABO letter refers only to this one antigen out of about 50 in the Rh system.
Q 22Roughly what share of Europeans lack the RhD antigen, compared with about 0.3% of Asians?
15%
The gap creates supply problems for Rh-negative Westerners needing blood in East Asia.
Q 23Which European people have the highest recorded frequency of blood lacking the D antigen, over 47%?
The Basques
Rh negativity means the RHD gene is missing or mutated.
Q 24The extremely rare Rhnull phenotype, lacking every Rh antigen, has been nicknamed what?
Karl Landsteiner
The World Health Organization has celebrated it on that date since 2005.
Q 15Which Czech serologist independently described four blood types in 1907, numbering them I to IV?
Jan Janský
His system was preferred in much of Europe while an almost identical American scheme by Moss confusingly reversed I and IV.
Q 16Which pair of physicians introduced the O designation in 1910, later adopted internationally?
Hirszfeld and von Dungern
The League of Nations' standardisation commission endorsed their naming in 1928.
Q 17A 1919 paper in The Lancet by the Hirszfelds was the first to show what?
Blood group frequencies differ between populations
They had typed thousands of soldiers of many nationalities on the Macedonian front.
Q 18Who demonstrated in 1924 that ABO groups are inherited as multiple alleles at a single locus?
Felix Bernstein
The correct inheritance pattern settled decades of confusion about how types pass from parents to children.
Q 19The 'Rh' in Rh factor was originally short for what?
Rhesus
The name is now considered a misnomer, since the human antigen turned out to differ from the monkey one, but it stuck.
Q 20How was the serum that led to the discovery of the Rh factor produced?
Immunising rabbits with rhesus macaque red cells
It reacted with about 85 percent of human red cells, which became the Rh-positive majority.
Golden blood
It has been identified in fewer than 50 people, though that figure is often misread as the number alive today.
Q 25When hemolytic disease of the newborn is fatal to the fetus, what is the condition called?
Hydrops fetalis
It classically arises when a D-negative mother forms anti-D antibodies after carrying a D-positive baby, and they attack a later pregnancy.
Q 26What injectable medication stops mothers who lack the D antigen from forming anti-D antibodies?
Rho(D) immune globulin
It is on the WHO List of Essential Medicines and is usually given at about 28 weeks and again after delivery.
Q 27People with the Bombay (hh) blood phenotype form antibodies against which antigen found on nearly all red cells?
H
They can only safely receive blood from other Bombay-phenotype donors, and the trait occurs in about 4 people per million.
Q 28The Bombay phenotype is far more common in its namesake city, at roughly what rate?
1 in 10,000
Worldwide the figure is closer to 4 per million.
Q 29Lacking the Duffy antigen gives resistance to which disease?
Malaria
The antigen is the receptor Plasmodium vivax uses to enter red cells, so Duffy-negative blood is common where the parasite is endemic.
Q 30The Duffy antigen is named after what?
The patient in whom it was found
Richard Duffy was a haemophiliac who had received many transfusions and developed the first anti-Fya antibody in 1950.