Blood Spatter Analysis
Presumptive Blood Test
Blood Typing
Chemiluminescence
Drug Testing
100
When measuring a blood drop, only the ________ part of it is included in the measurement
Main body
100
What is the name of the presumptive blood test we did in lab?
The Kastle-Meyer test
100
What are the 8 blood types we learned about in class?
A+, A-, B+, B-, AB+, AB-, O+, O-
100
What chemical is mixed with blood to generate a glowing reaction?
Luminol
100
What is the name of the forensic science field in which scientists can test bodily fluids and tissues to detect the presence of poisons?
Toxicology
200
If the tail of a bloodstain points to the right, which direction is the blood travelling?
To the right
200
What term is used to describe a test result of (1) definitely not being a certain substance and (2) can probably be a certain substance?
Presumptive
200
What blood types can a person with blood type AB- donate to?
AB-, AB+
200
What element in the blood protein hemoglobin catalyzes the chemiluminescent reaction?
Iron
200
When iodine is mixed with cornstarch, what color is formed?
Dark purple / black
300
What trigonometric function is used to determine a blood stain's point of origin?
Sine
300
Name 2 reasons why the Kastle-Meyer test is performed at crime scenes instead of sending every possible bloodstain to the forensics lab.
The test is cheap, easy to do (simple/common materials needed), and provides a quick response.
300
What are 2 terms used to describe the development of a solid when two incompatible blood types are mixed?
Agglutination and precipitation
300
Name 1 chemical that can provide a false positive reaction
Bleach. Urine with low levels of blood. Stool with blood or peroxidase enzymes.
300
Which chili ingredient was contaminated by acetylsalicylic acid?
Sugar
400
What are the 4 parts of a blood drop?
Main body, spine, satellite, and tail
400
List 3 chemicals needed to perform the presumptive blood test. Spelling counts!
Ethanol, phenolphthalein, and hydrogen peroxide
400
While performing a blood typing analysis on a human blood sample, a forensic scientist observes an agglutination reaction in the B antigen and Rh antigen wells. What blood type does the analyzed blood sample have?
B+
400
Provide 1 reason why crime scene investigators will not automatically spray luminol all over a crime scene when they suspect a crime involving blood has been committed.
The luminol can destroy other evidence (proteins, enzymes, and genetic markers). The chemiluminescent reaction fades quickly (about 30 seconds for most human blood stains). The environment needs to be dark (outdoors scenes during the daytime will not be desirable).
400
Double Jeopardy
Place your wager
500
What type of surface leads to little/no distortion of the blood drop shape?
A smooth, nonporous surface
500
Explain why the presumptive blood test cannot provide definitive test results when analyzing suspects' blood samples.
This test may yield positive results for animal blood as well as human blood. It can also yield a positive result for any substance that contains oxidizing reagents, such as the peroxidase enzyme found in broccoli and cauliflower. Because it cannot rule out the possibility of an unknown sample as being human blood, animal blood, or some vegetables, its result is considered presumptive.
500
Explain why a person with blood type O- is considered to be the universal donor. Your explanation must include these terms: A antigen, B antigen, Rh factor antigen.
A person with blood type O- is the universal blood donor because they do not have the A antigen, B antigen, or Rh factor antigen. Not having these antigens means that there is no possible way that an unintended dangerous agglutination reaction can occur during a blood transfusion.
500
Our luminol solution was prepared by dissolving the luminol powder in distilled water. Since luminol reacts in the presence of an oxidizing agent, name another chemical we've used in one of the labs this semester that can be used to enhance the intensity of the blue color in a chemiluminescent reaction. Hint: consider which chemicals have oxygen atoms
Hydrogen peroxide
500
When ferrous sulfate mixes with sodium hydroxide, what is the name of the green colored solid that forms?
Ferrous hydroxide
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