PLTW PBS EOC 2026 Unit 2

unit 2

What is homeostasis, and how do organisms maintain it?

Stable regulation of internal systems maintained through negative feedback loops

What are the normal ranges for adult blood pressure and heart rate?

Blood Pressure: Less than 120/80 mmHg

Heart Rate: 60 to 100 beats per minute at rest

What does a high blood pressure indicate?

Suggests cardiac stress, blockages, systemic hypertension, or infection

What does a low blood pressure indicate?

Points toward structural heart weakness, dehydration, or dangerous blood loss

What happens in the body when systolic pressure is measured, and how is it heard?

The heart pumps blood out into the arteries; heard as the first tapping sound

What happens in the body when diastolic pressure is measured, and how is it heard?

The heart ventricles refill with blood; marked by the complete disappearance of sound

What does BMI measure and how do you calculate it?

Evaluates body fat based on weight and height

Identify signs of medical problems found during a visual inspection

Skin: Yellow jaundice (liver malfunction), pale blue cyanosis (oxygen deprivation)

Throat/Eyes: Swollen lymph nodes, infected tonsil streaks, sluggish pupils

What is a doctor looking for when listening to heart and lung sounds?

Heart: Clear opening and closing patterns free of murmurs or structural clicking

Lungs: Unobstructed breathing free of wheezing, crackles, or fluid rattling

What are doctors looking for during a neurological assessment?

Clear motor reflex responses, normal gait coordination, and proper cranial nerve tracking

Why does the body need cholesterol?

Used to synthesize stable cell membranes, build steroid hormones, and produce vitamin D

Why is having too much cholesterol in the body bad?

It forms calcified arterial plaques that block blood flow and cause heart attacks

Differentiate between LDL and HDL functions and ideal levels.

LDL (Low-Density Lipoprotein): Deposits cholesterol in the arteries; a person wants a low LDL value

HDL (High-Density Lipoprotein): Clears blood cholesterol to the liver; a person wants a high HDL value

What is atherosclerosis and how does it affect blood pressure?

Fat deposits narrow artery paths, which raises systemic blood pressure

Explain the energetic relationship between food, glucose, and ATP

Cells convert glucose from digested food into ATP energy currency

What are the 4 macromolecule classes?

Carbohydrates, Lipids, Proteins, Nucleic Acids

What are Carbohydrates

Quick-access primary energy fuel source

What are lipids?

Long-term energy storage insulation and cell boundary lipids

What are proteins?

Direct molecular machines executing cellular structural tasks

What are nucleic acids?

information blueprints storing hereditary genetic master files

How does insulin help body cells use glucose?

Insulin attaches to a cell receptor, triggering GLUT4 transporters to open the membrane

How do insulin and glucagon coordinate homeostasis, and what feedback type is this?

Insulin lowers blood sugar spikes, while glucagon elevates low blood sugar

Explain the core differences between Type 1 and Type 2 Diabetes

Type 1: An autoimmune disease where the pancreas cannot produce insulin; treated with insulin injections

Type 2: Metabolic resistance where receptors ignore insulin; managed with diet, exercise, and medication

What is HIPAA?

Health Insurance Portability and Accountability Act: Law protecting patient privacy

Differentiate between a Chronic and an Acute condition

Chronic: A persistent, long-lasting condition developing over years (e.g., cardiovascular disease)

Acute: A sudden, rapid-onset injury requiring immediate treatment

What is the purpose of mitosis and what happens to chromosomes?

Creates identical cell copies; chromosomes duplicate and separate equally

What makes cancer cells different from normal cells?

Cancer cells ignore cycle regulators, divide uncontrollably, and migrate to colonize other tissues

Where do transcription and translation take place, and what are their products?

Transcription: Happens in the nucleus; produces an mRNA copy from DNA instructions

Translation: Happens at a ribosome in the cytoplasm; synthesizes an active protein chain

Explain how substitution, insertion, and deletion mutations form, and their relative impacts

Substitution: Swaps a single base; usually alters only one amino acid

Insertion / Deletion: Adds or removes a base, shifting the reading frame and changing all downstream amino acids

Allele vs Gene

A gene is a DNA instruction trait; an allele is a specific version of that trait

Dominant vs. Recessive

Dominant alleles mask recessive ones when paired together

Heterozygous vs. Homozygous

Heterozygous has different alleles (Aa); homozygous has identical alleles (aa)

Genotype vs. Phenotype

Genotype is the genetic code sequence; phenotype is the physical trait expressed

Why are pedigrees useful, and what can they tell you?

They track inherited traits across family generations to deduce dominant or recessive inheritance patterns

Differentiate between autosomes and sex chromosomes

Autosomes: Chromosome pairs 1 through 22, which regulate general body traits

Sex Chromosomes: The 23rd pair (XX or XY), which determines biological sex

What is a karyotype and how is it organized?

A visual chart of an individual's chromosomes, paired and ordered from largest to smallest to spot abnormalities

What is nondisjunction and how does it happen?

Chromosomes fail to separate correctly during meiosis, causing gametes to have extra or missing chromosomes

Deletion

A segment of the chromosome is completely lost

Insertion

A segment from another chromosome is added

Inversion

A chromosome segment breaks off, flips backwards, and reattache

Duplication

A section of the chromosome is copied twice

translocation

two different chromosomes swap segments