Before doing this lab, I knew what the different blood types were: A, B, AB, and O. However, I never knew what these meant or why they were different. It’s all based on the DNA found on the red blood cells. A and B are the two types of proteins and a person can have one of these (A or B), both of them (AB), or none of them (O). This difference in proteins causes differences in the antibodies that are found in the person’s blood stream. People with A blood type have b antibodies, people with B blood type have a antibodies, people with AB blood type have no antibodies, and people with O blood type have both a and b antibodies. The antibodies are what cause problems in blood transfusions. For example, a person with A blood type can not receive B blood because their b antibodies reject it and cause clumping. This makes people with AB blood able to receive any blood type because they have no antibodies. Blood types can be useful for narrowing down a suspect pool, but they can not be used to identify someone. Blood types come from the red blood cells and these cells do not have nuclei. This means they contain no DNA for testing. This labs makes me want to find out what effects the different blood types have on people. The difference in antibodies most likely affects how well a person’s immune system defends the body. More antibodies seems like a good thing in that respect, so I would think that people with O blood have the best immune systems while the people with AB blood have the worst. I am not sure what other types of effects blood types could have on the human body, but I may research it more at some point.