Module 4: Phys. Ev. Hair, Blood, And Fingerprints

Question 1

1600s Antonio van Leeuwenhoek

Answer 1

• Developed first known microscope

- Had a single magnifying lens

Question 2

1655 Robert Hooke

Answer 2

• Developed the first compound microscope
• Examined thin slices of cork
• Named cells
• Other scientists hypothesized that cells are a basic unit of life

Question 3

1833 Robert Brown

Answer 3

• First scientist to publish findings on the cell nucleus
  
  • Used plant cells
• Cells were recognized as building blocks of living tissue

Question 4

1838 M. J. Schleiden

Answer 4

• Published a conclusion that all plant tissues had cells
  
  • Therefore all plants arose from cells
• Cell division work was incorrect

Question 5

1839 Theodor Schawn

Answer 5

• Extended cell theory to animals
• Cells are organisms
  
  • All organisms consist of one or more cells
  • Cells are basic unit structure for all organisms

Question 6

1840 Albrecht von Roelliker

Answer 6

-Sperms and eggs are cells

Question 7

1855 Rudolf Virchow

Answer 7

• All cells come from previous cells

- Contradicts spontaneous generation

Question 8

1862 Louis Pasteur

Answer 8

-Supported the theory that cells come from other cells

Question 9

Hair Morphology

Answer 9

The form and structure of hair

• Samples typically collected from diff. areas of the scalp and pubic areas
  
  • Pulled or cut off from skin line
  • To ensure that unique form and color variation Is available
  • See if hair is dyed or bleached
  • Avg. hair growth at 1cm per month
• Race can be determined
  
  • Pigment distribution
  • Texture
  • Cross section shape
• Can tell if hair fell out or was pulled
  
  • Follicular tissue

Question 10

Medulla

Answer 10

A set of cells that runs through a hair

-Used to determine if hair came from a person or animal

Question 11

Nuclear DNA

Answer 11

DNA that is found in the nucleus of the cell

• Hair
  
  • Found in Follicular Tissue

Question 12

Mitochondrial DNA

Answer 12

Found in mitochondria of the cell

• Hair
  
  • More common than nuclear DNA

Question 13

A-B-O System

Answer 13

Categorizes blood into three different types

• Later expanded after Rh factor was discovered
  
  • A, B, AB, O
  • • or - indicates the presence or absence of the Rh Factor
• Not used in linking blood to individuals, DNA is now used more commonly

Question 14

Hemostasis

Answer 14

The process where blood forms clots

Question 15

Vasoconstriction

Answer 15

The constriction of damaged vessels.

• Temporarily decreases blood flows and pressure
  
  • Pressure on a bleeding wound

Question 16

Platelet Plug Forms

Answer 16

When platelet sticks to the exposed collagen and become activated, which releases cells into the area creating a plug.

Question 17

Clotting of Blood

Answer 17

Happens when reactions reinforce the platelet plug, which creates a plug
-Could also promote platelet adhesion and collection in a damaged area

Question 18

Kastle-Meyer Color Test

Answer 18

Test that involves mixing a sample of a dried substance with chemical phenolphthalein and hydrogen peroxide

• If substance is blood, hemoglobin turns a deep pink
• Vegetable such as horseradish may turn pink

Question 19

Hemoglobin

Answer 19

Protein which transports oxygen and gives blood the red coloring

Question 20

Hemastix Strip

Answer 20

A color test in which distilled water moistens the strip and can determine if the substance is blood
-Will turn green in this case

Question 21

Luminol Test

Answer 21

Where luminol is sprayed on surfaces and stains to see if there is blood. Blood emits luminescence when dark enough.

• Can even pick up traces of dried blood
• Has no effect after DNA tests

Question 22

Precipitin Test

Answer 22

Used to determine if blood came from a human or an animal

• Human blood is put in an antiserum and will form a cloudy ring
• Can be used on dried blood that is 10-15 years old

Question 23

Herbert L. MacDonell

Answer 23

Studied bloodstains and has critical observations about bloodstains.

• It is important to keep note of the texture of a surface of where the blood lands
  
  • Blood splatters less when it hits a hard low porous surface
• Direction of travel can be seen
• Angles can be determined with the pattern, where the body was found and witness accounts
• Even without witness accounts, it can still be determined if a victim was standing
• Can also determine if the person was punched either once or more times

Question 24

Latent Fingerprints

Answer 24

Fingerprints made by oil and perspiration

Question 25

Visible Fingerepints

Answer 25

Created by when a surface is touched after the finger had contact with another substance

• Ink
• Blood
• Paint

Question 26

Plastic Prints

Answer 26

Are made when the finger touches a soft material

• Soap
• Putty

Question 27

Reflected Ultraviolet Imaging System (RUVIS)

Answer 27

Aims UV light at areas to find fingerprints