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PBS Unit 1 - Review Sheet

Whats Covered in this Review Sheet

            1. Processing a Crime Scene
            2. Fingerprints & Hair
            3. Blood Testing
            4. Glastier Equation
            5. Standard Curves & Correlation
            6. DNA Structure
            7. Polymerase Chain Reaction
            8. Restriction Enzymes
            9. DNA Gel Electrophoresis
            10. Manner of Death & Cause of Death
            11. Body Systems
            12. HIPAA

Processing a Crime Scene (Activity 1.1.1 - Investigating the Scene)


  1. Record

    • Position of Victim
    • Evidence
    • Layout


  1. Diagram





  1. Close/ High Quality 
  2. Include Ruler


  1. Questions
    1. What happened?
    2. Was it a crime?
    3. How did it happen?
  2. Develop hypothesis.

Collect Evidence

  1. Link evidence to tell a story
  2. Analyze evidence
  3. Avoid contaimination


  1. Search Method
  2. Mark Evidence





Evidence (Activity 1.1.4 - The Evidence)

Fingerprint Patterns

                  Loop                                   Whorl                                  Arch

Three types of fingerprints: loop, whorl, and arch.

Hair Structure

  • Cuticle – Outermost layer; covers/ protects the hair
  • Cortex – Between cuticle and medulla; contains pigment (melanin) for hair color; thickest layer.
  • Medulla – Innermost layer; soft/ fragile.


→ Activity 1.1.4 – The Evidence

Blood Testing (Activity 1.1.4 - The Evidence)

Blood Type A

  • Antigens: A
  • Antibodies: B

Blood Type B

  • Antigens: B
  • Antibodies: A

Blood Type AB

  • Antigens: AB
  • Antibodies: none

Blood Type O

  • Antigens: none
  • Antibodies: AB
Title: ABO Blood Groups | Author: OpenStax | Published: Wikimedia Commons | License: CC BY 3.0

Glastier Equation (Activity 1.1.5 - Time of Death)

Title: Glastier Equation | Author: Psiĥedelisto | Published: Wikimedia Commons | License: Public Domain

Standard Curve & Correlation (Activity 1.1.6 - Blood Spatter)

Example of a best-fit line.
Title: | Author: OpenStax | Published: OpenStax | License: CC BY 3.0

Linear Regression – Best Fit Line

    1.  A linear regression – or best-fit line – attempts to represent data points in a scatter plot as a representative trend. 

    2. Equation: $y = mx + b$

$y$ = y variable
$m$ = slope
$x$ = x variable
$b$ = y intercept

Examples of positive correlation, negative correlation and no correlation.
Title:  | Author: OpenStax | Published: OpenStax | License: CC BY 3.0

Nucleotides (Activity 1.2.1 - What is DNA?)

A phosphate group, deoxyribose sugar and a nitrogen base are all the components that make up a nucleotide. The organization of each structural component can be seen to the right.


Function: Nucleotides are marcomolecule-monomers that can be brought together to create a DNA polymer; they are the ‘building blocks’ of DNA.


DNA nucleotide with different colors for the phosphate group, deoxyribose sugar and nitrogen base.



Nitrogen Bases (Activity 1.2.1 - What is DNA?)


  1. Double-ring structure
  2. Guanine base pairs with Cytosine
    • • They share 3 hydrogen bonds
  3. Adenine base pairs with Thymine
    • • They share 2 hydrogen bonds
Purine Nitrogen Bases in DNA


  1. Single-ring structure
  2. Cytosine base pairs with Guanine 
    • • They share 3 hydrogen bonds
  3. Thymine base pairs with Adenine
    • • They share 2 hydrogen bonds
Pyrimidine Nitrogen Bases in DNA

Polymerase Chain Reaction (Activity 1.2.3 - DNA Analysis)

Step 1 – Denaturation

  1. Raise the temperature.
  2. As a result, the hydrogen bonds in the DNA double strand break and the molecule separates into two separate DNA single strands. (Excuse the alliteration!)

Step 2 – Annealing

  1. Cool the temperature down a bit.
  2. This will allow primers to attach to complimentary sequences on each of the single stranded DNA.

Step 3 – Elongation

  1. Slightly raise the temperature
  2. Taq polymerase will interact with the DNA-primer complex and begin to add nucleotides to the 3′ end of the primer. These nucleotides will be complimentary to whatever nucleotides are on the DNA strand.

Polymerase chain reaction
Title: Polymerase Chain Reaction | Author: Enzoklop | Published: Wikimedia Commons | License: CC BY-SA 3.0

Restriction Endonucleases (Activity 1.2.3 - DNA Analysis)

Origin: Restriction enzymes are produced by bacteria to protect the bacterium from foreign, viral DNA.


Function: They recognize a short, specific nucleotide sequences and separate the DNA strands at precise locations.


Application: Scientists have isolated restriction enzymes from bacteria and used them for techniques like genetic cloning and gel electrophoresis.

Restriction enzyme BamHI cuts DNA
Title: BamHI | Author: Simon Caulton | Published: Wikimedia Commons | License: CC BY-SA 4.0

Gel Electrophoresis (Activity 1.2.3 - DNA Analysis)

: DNA gel electrophoresis attempts to separate DNA fragments according to the size of the fragments. 


Function: The DNA sample is loaded into the wells of the gel and a current is applied to the electrophoresis chamber which also contains a salt water buffer. The DNA is moves towards the positive electrode in response to an applied current. Larger DNA fragments move slower through the agarose molecules in the gel.


Application: Gel electrophoresis can be used to analyze and compare the RFLPs of an unknown genetic sample to known genetic samples. For example, DNA evidence at a crime scene can be compared to a series of potential suspects.


DNA gel electrophoresis chamber setup.
Title: DNA Gel Electrophoresis| Author: Genome Research Limited | Published: yourgenome | License: CC BY 4.0

Autopsy (Activity 1.3.1 - Autopsy)

Manner of Death

    1. Homicide 
    2. Suicide
    3. Accidental
    4. Natural
    5. Undetermined
    6. Pending

Cause of Death – What specifically caused the death?

Medical Examiner 

    • Physician; Medical Doctor
    • Preform autopsies
    • Determine manner & cause of death


    • Appointed official
    • Investigates the death.
    • Determine manner & cause of death

Body Systems (Activity 1.3.1 - Autopsy)

Integumentary System

    • Structures – skin; hair; nails
    • Function – protection

Nervous System

    • Structure – brain; spinal cord; nerves
    • Function – communication

Digestive System

    • Structure – oral cavity; esophagus; stomach; intestines 
    • Function – water and energy absorption; solid waste

Respiratory System

    • Structure – nasal passage; trachea; lungs; bronchi; aveoli
    • Function – gas exchange

Urinary System

    • Structure – kidney; ureter; bladder; urethra
    • Function – water absorption; liquid waste

Endocrine System

    • Structure – pituitary gland; adrenal gland; ovaries; testes
    • Function – hormone regulation; communication

Lymphatic & Immune System

    • Structure – lymph nodes; thymus; spleen; bone marrow
    • Function – filtration of toxins and waste; immunity

Skeletal System

    • Structure – bones; joints
    • Function – structure; protection

Muscular System

    • Structure – skeletal muscle; smooth muscle; cardiac muscle
    • Function – movement; heat

Cardiovascular System

    • Structure – heart; arteries; veins; capillaries
    • Function – circulate blood; gas exchange

Health Insurance Portability & Accountability Act (Activity 1.3.2 - Confidentiality)

 Author: Center for Disease Control | License: Public Domain (edited)