PLTW PBS end of course exam UNIT 1

eoc 2026

What are physiological responses measured during a polygraph test?

heart rate, blood pressure, skin conductivity, respiratory rate, and temperature

Why is it important to establish baselines during a polygraph test

to compare physiological responses against regular levels for accuracy.

Are polygraph tests 100% reliable?

No, polygraph tests are not 100% reliable; they can produce false positives and false negatives.

Testable hypothesis outline

if (independent variable), then (dependent variable)

independent vs. dependent variable

The independent variable is the factor manipulated in an experiment, while the dependent variable is the observed outcome affected by changes in the independent variable.

what is a control?

an element, subject, group that remains unchanged or unexposed to the tested variable. acts as a baseline to determine whether the experiments

results were actually caused by the independent variable

what is a hair cuticle?

transparent outer protective layer of the hair

what is the cortex?

the thick core responsible for the hairs strength and color

what is the medulla?

internal core, full of loosely packed keratinized cells, sometimes absent or very thin

what type of fingerprint is this?

arch

what type of fingerprint is this?

tented arch

what type of fingerprint is this?

loop

what type of fingerprint is this?

whorl

define fingerprint minutiae

tiny, unique ridge characteristics used to match fingerprints

how many minutiae must be matched to establish an indentical fingerprint?

12-15 matching prints must be seen to establish an identity in the court of law

What are 4 main components of blood?

plasma, red blood cells (erythrocytes), white blood cells (leukocytes), platelets

What is plasma?

Liquid vehicle carrying blood components, nutrients, and waste products

What are red blood cells (eyrthrocytes)?

Transport oxygen using hemoglobin proteins

What are white blood cells (leukocytes)

Immune defense cells targeting foreign pathogens

What are platelets (Thrombocytes)?

Cell fragments essential for initiating clotting

Purpose of a presumptive test?

Preliminary field tests indicating a substance is highly likely blood (e.g., Kastle-Meyer)

Purpose of a confirmatory test?

Advanced laboratory tests identifying blood with absolute chemical certainty (e.g., RSID)

What are antigens?

Foreign or self-identifying cell surface proteins provoking an immune response

Which antigens do people with type A blood have on their cells?

A antigens

Which antigens do people with type B blood have on their cells?

B antigens

Which antigens do people with type AB blood have on their cells?

Both A and B antigens

Which antigens do people with type O blood have on their cells?

Neither A nor B antigen

How do height and angle affect blood spatter patterns?

Drops falling from higher points yield larger stain diameters with more satellite spatter, 90 degree angle hits form circular stains; narrow impact angles yield long, elongated teardrop paths

What are the three components of a nucleotide?

A deoxyribose sugar molecule, a phosphate chemical group, and a nitrogenous ring base

How do bases of DNA pair together?

Adenine always pairs with Thymine ; Guanine always pairs with Cytosine

What is a gene?

A specific segment of DNA base pairs that provides instructions to create a specific protein

What is a chromosome?

An organized structural bundle of DNA found inside the nucleus

Explain the exact physical relationship between DNA, genes, and chromosomes

Chromosomes are built from a long chain of coiled DNA, and individual active sections along that strand are called genes

What is a eukaryotic cell?

feature membrane-bound organelles and a true nucleus

What is a prokaryotic cell?

Lack a membrane-bound nucleus and do not house internal organelles

Explain how PCR helps to establish a DNA profile?

Amplifies tiny DNA trace samples to produce millions of workable matching copies

Explain how a restriction enzyme helps to establish a DNA profile?

Chemically cut the amplified DNA strand at precise target sequences

Explain how gel electrophoresis helps to establish a DNA profile?

Drags fragments using an electrical current through a gel to sort them by length

During gel electrophoresis, in which direction do the DNA fragments move and why?

DNA contains negative phosphate backbones attracted toward positive anodes

Which fragments will move through the gel matrix faster

Smaller fragments slip through the microscopic holes faster than heavy, long fragment

Cause of death

The injury or disease that starts the fatal event sequence (e.g., blunt-force head trauma)

Manner of death

The legal, administrative category of death (e.g., Homicide, Accident, Natural, Suicide

Mechanism of death

The specific physiological organ failure that stops life functions (e.g., cerebral hypoxia)

What is the cardiovascular system?

ransports blood containing gases, signaling hormones, and nutrients

What is the urinary system?

Filters blood plasma to discard metabolic nitrogenous waste and maintain hydration

What is the respiratory system?

Transfers atmospheric oxygen into blood while exhaling carbon dioxide

What is the digestive system

Chemically and mechanically breaks down consumed food for cellular energy absorption

What is the immune system?

Defends internal body structures from microscopic biological invaders

What is the nervous system

Evaluates incoming sensations to direct behavioral motor responses

What is the endocrine system?

Coordinates growth and homeostasis rhythms using targeted hormone release

Algor Mortis

Postmortem body temperature loss drops roughly 1.5 degrees per hour

Rigor Mortis

Muscle freezing occurs 2–4 hours after death due to a lack of ATP production

What is livor mortis?

Blood pooling yields red-purple skin discoloration on surfaces touching the ground

What is the significance of insect activity in a dead body?

Forensic entomologists study blowfly larvae age to calculate postmortem intervals

Provide an example for each structural Level of Organization

Cell (Myocyte), Tissue (Muscle tissue), Organ (Heart), Organ System (Cardiovascular)

What is the frontal lobe?

Coordinates planning, decisions, reasoning, and voluntary muscle action

What is the paretial lobe?

Translates bodily sensations including touch, temperature, and spatial positioning

What is the temporal lobe?

Evaluates auditory sound inputs and forms long-term memories

What is the occipital lobe?

Processes direct sensory input received from the eyes

What is a TBI

An acute head trauma event from an immediate blow, resulting in a sudden concussion

What is a CTE

Chronic tissue degeneration from repeated head hits over time, causing depression and memory loss

Epithelial tissue

Protective sheets lining organs and outer body boundaries

What is connective tissue?

Structural matrix supporting other tissues

what is muscle tissue?

Specialized contracting fibers allowing motor movement

What is nervous tissue?

Electrical communication network transmitting fast signals

List the correct path of blood through the cardiovascular system starting at the Vena Cava

Superior/Inferior Vena Cava, Right Atrium, Tricuspid Valve, Right Ventricle, Pulmonary Valve, Pulmonary Artery , Lungs, Pulmonary Veins , Left Atrium , Bicuspid (Mitral) Valve, Left Ventricle, Aortic Valve , Aorta, Systemic Body Tissues

What is a valve defect?

Cause blood backflow due to leaflets leaking or failing to open fully

What is a septal defect?

Structural holes in the interior wall allowing deoxygenated and oxygenated blood to mix