Hair
Where can DNA be found in the hair?
Root
Name a natural fiber that comes from plants
Silk, Cotton
A, B, AB, O
What are the three basic types of fingerprints?
Loop, whorl, and arch.
What does DNA stand for?
Deoxyribonucleic acid.
How can you tell if hair is human or animal?
Inspecting the medulla
Natural fibers come from plants or animals, while synthetic fibers are man-made from polymers.
What does blood impact at an angle tell you?
Directionality, height
What are fingerprints composed of?
Oil and sweat
Adenine, Thymine, Cytosine, and Guanine.
What technique is commonly used to analyze hair
Light Microscopy
What tool is commonly used to examine the cross-section of a fiber?
Light microscope
The difference between a swipe and a wipe is:
Swipe - Bloody item, clean surface
Wipe - Non Bloody item, bloody surface
When do fingerprints develop for humans?
What is the shape of DNA?
Double Helix
Pigment is found where in the hair?
Cuticle
What is one way forensic scientists differentiate between fibers at a crime scene?
By performing a burn test to analyze melting or ash residue.
What are passive and active stains?
Passive - No outside force
Active - Outside force
What kinds of surfaces are easy to lift fingerprints off of?
Non - Porous, smooth
Difference between mitochondrial and nuclear DNA?
Nuclear DNA is inherited from both parents, while mitochondrial DNA is inherited only from the mother.
The 3 layers of hair are:
Cuticle, Cortex, Medulla
The 6 fibers we investigated in this class were:
How does a high-velocity blood spatter differ from a low-velocity blood spatter?
High-velocity spatter produces smaller droplets, often from gunshots; low-velocity spatter produces larger droplets, typically from blunt force.
What makes a fingerprint "Accidental"
What is gel electrophoresis used for in DNA analysis?
To separate DNA samples by size