Forensic Science Overview

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Questions and Answers

What type of fingerprint pattern has ridges that form circles or spirals?

Loop

Arch

Tented Arch

Whorl (correct)

Which layer of hair is the thickest?

Epidermis

Cortex (correct)

Cuticle

Medulla

What is the minimum number of minutiae required to establish an identical fingerprint?

12 (correct)

Which type of fingerprint has a pronounced upward thrust or spike in the center?

Tented Arch Signup and view all the answers

What are independent variables in an experiment?

Variables that are changed to observe effects. Signup and view all the answers

What does rigor mortis indicate about a deceased person's condition?

The muscles and joints have become stiff. Signup and view all the answers

Which of the following tissues is primarily responsible for contraction and movement?

Muscle tissue Signup and view all the answers

How do valve defects differ from septal defects in heart conditions?

Valve defects pertain to malfunctioning valves, while septal defects involve a hole in the wall. Signup and view all the answers

Which brain lobe is responsible for processing auditory information and memory?

Temporal lobe Signup and view all the answers

Which type of tissue functions to cover and line surfaces in the body?

Epithelial tissue Signup and view all the answers

What component of blood is responsible for carrying oxygen?

Red blood cells Signup and view all the answers

What is the primary function of a confirmatory test in analysis?

To definitively identify a substance Signup and view all the answers

Which blood type has the presence of A and B antigens?

Type AB Signup and view all the answers

How does angle of impact affect the appearance of a bloodstain?

A lower angle produces elongated stains Signup and view all the answers

What are the three components of a nucleotide?

Nitrogenous base, pentose sugar, phosphate group Signup and view all the answers

What is the primary function of genes within chromosomes?

They are the functional units of heredity. Signup and view all the answers

How do prokaryotic cells differ from eukaryotic cells?

Prokaryotic cells lack a nucleus. Signup and view all the answers

What is the purpose of gel electrophoresis in DNA profiling?

To separate DNA fragments based on size. Signup and view all the answers

During gel electrophoresis, why do smaller DNA fragments move further than larger ones?

They pass through larger pores more easily. Signup and view all the answers

Which of the following correctly defines 'Cause of Death'?

The specific disease or injury initiating death. Signup and view all the answers

In the context of autopsy terminology, what does 'Manner of Death' describe?

The circumstances under which death occurred. Signup and view all the answers

Which organ is primarily associated with the Urinary System?

Bladder Signup and view all the answers

What physiological process directly caused the body's failure, often termed as the Mechanism of Death?

Blood loss Signup and view all the answers

Study Notes

Polygraph

Polygraph tests measure physiological responses to detect deception
Physiological responses include heartbeat rate and breathing speed
Polygraph tests are used to detect if a person is lying or not
Baselines are established to determine a person's normal range of heartbeat or intervals
Polygraph tests are not 100% reliable

Experimental Design

Testable hypothesis: Salt dissolves in hot water faster than sugar
Independent variable: the variable changed to affect the results
Dependent variable: the variable being measured in an experiment
Control variable: A dependent variable that is not affected by the independent variable
It acts as a baseline

Hair Structure

Cuticle: Outermost layer of hair, made of overlapping dead cells
Cortex: Middle layer of hair, thickest layer
Both these layers play a critical role in protecting and maintaining the structural integrity of the hair shaft.

Fingerprints

Arch: Ridges flow from one side to the other, least common
Tented Arch: Similar to arches but with a more pronounced spike
Loop: Ridges flow in one side, recurve, and exit on the same side (radial or ulnar)
Whorl: Ridges form circles or spirals, classified as plain, central pocket, double loop, or accidental
Minutiae: Tiny details in fingerprints that make them unique
Identical fingerprint matching requires 12 minutiae matches

Blood Components

Red blood cells (erythrocytes): Carry oxygen
White blood cells (leukocytes): Fight infection
Platelets (thrombocytes): Help with blood clotting
Plasma: Liquid component carrying other blood cells and substances

Blood Types

Antigens: Molecules on blood cells triggering immune response
Blood types (A, B, AB, O) are determined by specific antigens present

Blood Spatter Analysis

Blood droplet size is affected by drop height and angle
Steeper drop angle creates elongated blood spatters
90-degree angle creates circular blood spatters

Nucleotide Structure

Nucleotide components: Nitrogenous base, pentose sugar, phosphate group

DNA Base Pairing

A pairs with T
G pairs with C

DNA Structure and Function

Deoxyribose sugar
Nitrogen bases
Nucleotides
Phosphate group
Genes: Specific segments of DNA
Chromosomes: DNA structures inside the nucleus
Genes are the functional units of heredity located on chromosomes

Prokaryotic vs Eukaryotic Cells

Prokaryotic: No Nucleus
Eukaryotic: Has a Nucleus

DNA Analysis/Profiling

PCR amplifies small amounts of DNA
Restriction enzymes cut DNA at specific sites creating unique fragment lengths
Gel electrophoresis separates fragments by size to visualize a DNA profile

Autopsy

Cause of death: The specific injury or disease that initiated the death sequence.
Manner of death: How the death occurred (e.g., homicide, suicide, accidental)
Mechanism of death: The physiological process that directly caused the body to stop functioning.

Body Systems

Organs matched with their respective systems (e.g., Heart–Cardiovascular).

Time of Death

Livor mortis, rigor mortis, algor mortis, insect activity
These factors can help estimate the time of death

Levels of Organization

Cell, Tissue, Organ, Organ System (e.g., Muscle tissue, Stomach, respiratory system, etc.) -

Brain Lobes

Frontal lobe: Planning, decision making
Parietal lobe: Sensory information (touch, taste)
Temporal lobe: Auditory information, memory
Occipital lobe: Visual information

TBI vs CTE

TBI: Single blow to the head
CTE: Multiple blows or repeated head trauma
Effects of CTE generally worse than TBI

Heart Defects

Valve defects: Valves do not open or close properly
Septal defects: Hole in the heart wall

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Description

This quiz explores various aspects of forensic science, including polygraph testing, experimental design in forensics, hair structure, and fingerprint analysis. Each section provides insights into the techniques and concepts used in forensic investigations. Test your knowledge on these critical topics in forensic science!