There are different Blood Types
Fact

There are four major ABO blood types, each can be Rh positive or negative. Beyond this there are many subtypes.

What are the Blood Types?

There are four general blood types (A, B, AB, and O), each can be Rh  ‘+’ or ‘-‘. Blood types differ by antigens on the surface of red blood cells. So generally, blood can have A, B, both A and B antigens, or neither, and can have Rh antigens or not.[1][2]

In more comprehensive terms, blood types actually differ by 35 blood groups systems of which the ABO blood antigen group and Rh blood antigen group are the most notable (as they are used for determining blood transfusions and mating compatibility).

Importantly, plasma (the technical name for blood) also includes white blood cells and platelets, along with the aforementioned red blood cells. All blood types are expressed due to slight genetic differences between humans.

What Are Blood Types?

FACT: Red blood cells are notable for being one of the few cells in our body that don’t contain DNA information, although the cells that produce them do. All cells that contain DNA share the same DNA.

Types of Plasma (Blood)

The three types of plasma are:

  • Red blood cells carry oxygen.
  • White blood cells fight infection.
  • Platelets stop bleeding in injuries.

Four Blood Types Infographic

Rh blood group and ABO blood group Types

There are 35 known blood groups systems, but the two main systems that determine mating and blood transfusions are Rh and ABO.

  • The ABO blood group system (as in A, B, or O) directly determines how blood can be shared for transfusions along with Rh. A means only the A antigen is there; B means only B; AB means A and B; and O means no A or B antigens (think ZERO, not the letter “O”). ABO is widely credited to have been discovered by the Austrian scientist Karl Landsteiner, who identified the O, A, and B blood types in 1900.[3]
  • Rh blood group system directly determines whether or not mating will be a problem. Either blood tests positive ‘+’ for the Rh antigen or it tests negative for the Rh antigen ‘-‘. The Rhesus blood type named after the Rhesus monkey was first discovered in 1937 by Karl Landsteiner and Alexander S. Wiener.[4]

Does blood type matter for pregnancy? Nothing inspires confidence like Dr. Oz, I know, but in this case, the advice is spot on.

TIP: The ‘O’ stands for zero. As in there are zero antigens on the red blood cell. The + or – means it tests positive or negative for the Rhesus blood type (i.e. it has the Rhesus antigen).

What are Antigens?

Antigens are proteins, carbohydrates, glycoproteins, or glycolipids (depending on the blood group system) that live in red blood cells. Antigens determine how compatible blood types are and what a child’s blood type will be. In other words, how well people can conceive babies, what medical intervention is likely to be needed as a result of conception, and how well blood can be shared in transfusions is 100% governed by Antigens, and the presence of Rh, and therefore blood types.

Different blood types often reject each other due to the foreign bodies (antigens) in the blood (see an exact matchup in the transfusion chart below).

Blood Types?

FACT: It’s common for a mother to have a different blood type than her fetus. However, with some blood types a mismatch can cause the woman’s antibodies to fight against the fetus. Specifically, mothers who are RhD- and carry a RhD+ baby can form antibodies against fetal RBCs.

What Blood Types are Compatible

There are four major blood types, and then each can be positive or negative. These eight total types are only compatible with certain other types, although AB+ specifically is compatible with all types.

This chart below shows the ONLY ways that blood must be matched for transfusion.

Red blood cell compatibility table (source)
Recipient[1] Donor[1]
O− O+ A− A+ B− B+ AB− AB+
O− Green tick Red X Red X Red X Red X Red X Red X Red X
O+ Green tick Green tick Red X Red X Red X Red X Red X Red X
A− Green tick Red X Green tick Red X Red X Red X Red X Red X
A+ Green tick Green tick Green tick Green tick Red X Red X Red X Red X
B− Green tick Red X Red X Red X Green tick Red X Red X Red X
B+ Green tick Green tick Red X Red X Green tick Green tick Red X Red X
AB− Green tick Red X Green tick Red X Green tick Red X Green tick Red X
AB+ Green tick Green tick Green tick Green tick Green tick Green tick Green tick Green tick

FACT: Blood type (or blood group) is determined, in part, by the ABO blood group antigens present on red blood cells.

How is Blood Type Inherited? How are Blood Types Determined?

A child’s blood type is inherited from it’s parents based solely on the parents blood-type. This is true for ABO and Rh respectively. Blood types have a percentage chance (probability) of occurring based on parent’s blood type. Some combinations are certain, some won’t be able to occur with specific parents, and some have only a chance of occurring (see charts below).

How is ABO Blood Type Inherited?

ABO blood type expression is controlled by a single gene. There are three “alleles” (alternatives) for how the gene is expressed. Each person has two ABO allele.

According to Wikipedia, because let’s be honest there is no reason to re-write this:

  • The IA allele gives type A, IB gives type B, and i gives type O.
  • Both IA and IB are dominant over i, so only ii people have type O blood.
  • Individuals with IAIA or IAi have type A blood, and individuals with IBIB or IBi have type B.
  • IAIB people have both phenotypes, because A and B express a special dominance relationship: codominance, which means that type A and B parents can have an AB child.
  • A couple with type A and type B can also have a type O child if they are both heterozygous (IBi,IAi).
Blood group inheritance (source)
Blood type O A B AB
Genotype ii (OO) IAi (AO) IAIA (AA) IBi (BO) IBIB (BB) IAIB (AB)
O ii (OO) O
OO OO OO OO
O or A
AO OO AO OO
A
AO AO AO AO
O or B
BO OO BO OO
B
BO BO BO BO
A or B
AO BO AO BO
A IAi (AO) O or A
AO AO OO OO
O or A
AA AO AO OO
A
AA AA AO AO
O, A, B or AB
AB AO BO OO
B or AB
AB AB BO BO
A, B or AB
AA AB AO BO
IAIA (AA) A
AO AO AO AO
A
AA AO AA AO
A
AA AA AA AA
A or AB
AB AO AB AO
AB
AB AB AB AB
A or AB
AA AB AA AB
B IBi (BO) O or B
BO BO OO OO
O, A, B or AB
AB BO AO OO
A or AB
AB AB AO AO
O or B
BB BO BO OO
B
BB BB BO BO
A, B or AB
AB BB AO BO
IBIB (BB) B
BO BO BO BO
B or AB
AB BO AB BO
AB
AB AB AB AB
B
BB BO BB BO
B
BB BB BB BB
B or AB
AB BB AB BB
AB IAIB (AB) A or B
AO AO BO BO
A, B or AB
AA AO AB BO
A or AB
AA AA AB AB
A, B or AB
AB AO BB BO
B or AB
AB AB BB BB
A, B, or AB
AA AB AB BB

How is Rh Blood Type Inherited?

Rh blood type works similar to ABO blood type. There are two “alleles” (alternatives) for how the gene is expressed, Rh+ and Rh-. Everyone has two Rh allele.[5]

  • If people have any Rh+ they are Rh+ (so both Rh+/Rh+, and Rh+/Rh-) are positive.
  • If people have two Rh- (Rh-/Rh-) they are Rh-.

Thus unless a mother and father are both Rh-, the child has a chance of being Rh+.

The other rules are:

  • A mother who is Rh- can only pass an Rh-.
  • A father who is Rh+ can pass either Rh+ or Rh-.

Like ABO, there is a rule-set for Rh and the rest is left up to chance. You can see basic Rh charts here.

Why Do We Have Different Blood Types?

It is thought that the blood types can be traced back to specific genetic differences between humans. It’s likely that genetic variations were mutations in response to diseases, but some speculate that it represents a split between Cro-Magnons and Neanderthals. This line of exploration obviously takes as far away from the Red Cross and into more philosophical lines of thinking, so let’s save that for the following YouTube video.

Human Blood Types?

Speculation aside, on the simplest level again, blood types has to be thought about in procreation and transfusions, and thus play a vital role in our every day life.



Conclusion

ABO type, Rh type, and related antigens determine our blood transfusion and mating compatibility, and the blood types of our children. Understanding the basics of blood systems is almost as important as giving blood.


References

  1. Blood Types” Redcrossblood.org
  2. Blood Type” Wikipedia.org
  3. ABO blood group system” Wikipedia.org
  4. Rh blood group system” Wikipedia.org
  5. Blood Types Tutorial” Arizona.edu


"There are Different Blood Types" is tagged with: Cells, DNA


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You Don't Want to Know on

This is true.

Dembie on

Since Eve was flesh of Adam’s flesh and bone of his bone, and blood is manufactured in the bone, they had the exact same blood type. That would show that there was no variation in blood types. Therefore, 4 different blood types cannot have evolved from two with the exact same DNA.

Thomas DeMichele
Thomas DeMichele on

Nice deductive logic!