Lab 9b Blood Typing

What is the blood type shown?

AB- (refer to image for more detail)

Does this mean the person whose sample was found at the crime scene is the killer? Explain.

After reviewing the evidence revealed by the crime scene blood typing results, there is a high probability that the person whose sample was found at the crime scene was the killer. Based on the tests run, it is clear to see that the blood found at the crime scene had agglutination occur in both the A and Rh wells, while the B well showed no change. This means that the blood found at the crime scene is A+. When running the same tests on the other suspects blood, only suspect 3 yielded the same results—A+. If utilizing the blood test alone, this could be enough to show that suspect three was the killer. However, there must be more evidence to be sufficient enough to incriminate the suspect.

Create a new chart using the insert table option above. Fill in the information below and then put your data in the correct columns:

Refer to image for details

Which suspects' blood was found at the crime scene?

Suspect 3

Describe, in your own words, what are the features of blood cells that make one person's blood type different than another person's blood type? Why do you think humans evolved different blood types?

The features of blood cells that make one person's blood type different than another person's blood type are the presence of small proteins on the surface. The proteins—or antigens—give each cell certain characteristics that make some people different from others. This is all thanks to genetic coding, or DNA. People with A blood produce A antigens, B produces B antigens, AB produces both, and O produces neither. Each blood type produces antibodies against whatever antigen they lack. Furthermore, Rh proteins determine if blood type is positive (meaning Rh antigens are present) or negative (meaning they are not). It is quite difficult to understand or theorize why humans have come to evolve different blood types. Blood typing may have once been more regional to protect against certain sickness or disease, and has ended up where it is today because of cultural blending and how people have come to travel the world.

Provide two additional types of evidence or information you would need in order to confidently conclude that the suspect whose blood was found at the crime scene is the killer.

When it comes to confidently determining if the suspect whose blood was found at the crime scene was the killer, I believe that a DNA test of each sample would be needed. DNA is unique to every individual, and if the DNA from the blood samples matched, then this could prove that the suspect is the killer. Furthermore, if fingerprints could be retrieved from the scene of the crime, I believe the minutiae could provide additional evidence along with the blood typing results to aid in confidently determining if the identified suspect is the killer.

What are some alternative explanations for the suspect's blood being found at the crime scene?

While it may seem fair to arrest suspect three based on the blood test alone, it is not enough evidence to prove that they are the killer. One alternate explanation for the suspect's blood being found at the crime scene is that maybe the actual killer just so happened to have the same blood typing at the suspect. A+ blood is not limited to the suspect, and many other human beings on this planet also have the A+. Furthermore, the suspect could have happened to be a bystander, and maybe they sustained a wound that just to happened to allow their blood to contaminate the crime scene. Speaking of which, another alternate explanation is that maybe the blood sample found at the scene of the crime was contaminated and does not show accurate results.

The process in which antibodies attach to antigens, causing the formation of clumps of cells, is called ________.

agglutination

Hemolytic disease of the newborn is a risk during a subsequent pregnancy in which ________.

an Rh− mother is carrying a second Rh+ fetus

People with type O blood________.

lack both antigens A and B on their erythrocytes

Anti-Rh Serum Anti-B Serum Anti-A Serum Type O- Blood Type AB+ Blood Type A+ Blood Type B- Blood

A liquid containing proteins called antibodies that bind to type RH protein markers (called antigens) on red blood cells A liquid containing proteins called antibodies that bind to type B protein markers (called antigens) on red blood cells A liquid containing proteins called antibodies that bind to type A protein markers (called antigens) on red blood cells Blood that does not contain A, B, or Rh antigens, can donate to all blood types-universal donor Blood that contains A, B, and Rh antigens, can receive all blood types-universal recipient Blood that contains A and Rh antigens Blood that contains B antigens only