Biology Exam

1.1 - Genetic Material DNA

• DNA (deoxyribonucleic acid):
  • A single, long molecule containing the genetic code of a living thing.
  • Shape: double helix.
  • Length: If stretched out, approximately 2-3 meters long.
  • Genetic Code: Pattern that instructs the body to produce specific proteins.
  • Proteins: Structures responsible for building and performing functions in the body.
  • Different proteins lead to different individual characteristics.
• DNA Storage inside the Cell:
  • Due to its length, DNA must be coiled and folded tightly within the nucleus, resembling a ball of yarn.
• DNA wrapped into Nucleosomes:
  • Nucleosome: Formed when DNA wraps around proteins called histones.
  • DNA wrapped around Histones = Nucleosomes wrapped into Chromatin.
• Chromatin wrapped into Chromosomes:
  • Chromatin is created when the nucleosomes are densely folded over one another to be compact in size.
• Chromatin wrapped into Chromosomes:
  • Chromatin further folds and layers until the entire DNA molecule condenses into a single chromosome.
  • 1 DNA molecule = 1 chromosome strand
• Human Chromosomes:
  • Typical human body cell contains 46 chromosomes.
• Gene Expression:
  • All cells contain all genes, but gene expression is cell-specific (e.g., skin cells don't produce mucus).
• Karyotype:
  • A chart organizing an organism's chromosomes into pairs of equal length (homologous), ordered from longest to shortest.
  • The last pair determines sex.
• Structure of a Chromosome:
  • Each band represents a specific gene (instructions for a cell).
  • Each gene occupies a specific locus (position).
  • Alleles: Different forms of a gene (e.g., eye color).
  • Centromere: Region crucial for cell division.
• Homologous Chromosomes:
  • Pairs of chromosomes within each nucleus with the same length and gene sequence.
  • Alleles may be the same or different.
  • Example: One parent has brown eyes, the other has green eyes.
• Other Key terms to know:
  • Genotype: The specific alleles a person has.
  • Phenotype: The actual trait a person has.
  • Note: Recessive genes may not be expressed.
• The 23rd Pair of Human Chromosomes:
  • X chromosome: Contains approximately 1400 genes.
  • Y chromosome: Contains approximately 200 genes.
  • Two X chromosomes: Female.
  • One X and one Y: Male.
  • X chromosome:
    • Codes for many Genes integral for growth and development (for all individuals).
  • Y chromosome:
    • Codes for comparatively less genes.
  • In humans, neither chromosome are expressed until about 6 weeks after conception, humans are phenotypically female (or agender).
  • Secondary sexual characteristics develop later in most humans.

1.2 - Gamete Production and Meiosis

• Sexual Reproduction:
  • Involves two parents reproducing to create unique offspring.
• Chromosomes:
  • Bundles of DNA; each species has a unique number.
  • Humans have 46 chromosomes.
• How many chromosomes in each gamete?
  • Cells contain DNA copies from both parents:
    • Haploid (n): One copy from each parent.
    • Diploid (2n): Combination of both copies.
• The Male Reproductive Organ:
  • Sperm cells: Male gametes, haploid (n=23 in humans), produced in the testes.
  • Spermatogenesis: Sperm production begins at puberty.
• Spermatogenesis:
  • Stem cells (2n = 46) in the testes undergo hormonal signaling at puberty to become sperm cells (n=23).
• The Female Reproductive Organ:
  • Egg cells: Female gametes, haploid (n=23 in humans), found in the ovaries.
• Oogenesis:
  • Females are born with egg cells that mature at puberty.
• Oogenesis:
  • Hormones signal one immature egg (2n = 46) monthly to mature into an egg (n=23) during the ovulation cycle.
• MEIOSIS:
  • Built-in mechanisms to share and change DNA to create more variation in offspring.
• Homologous chromosomes are NOT identical, but code for the same traits
  • Chromatin: Uncoiled DNA being used by the cell
  • Chromosome: Coiled DNA for ease of replication
  • Sister Chromatids: Identical chromosomes (an original and a copy) attached by a centromere
  • Homologous Chromosomes: Two different chromosomes that code for the same genes (different alleles) Typically get one from each parent
• INTERPHASE
  • Growth and synthesis phase before dividing Replication of chromosomes
  • Therefore at the beginning of meiosis, a cell contains duplicated chromosomes Each chromosome is made up of a pair of identical sister chromatids held together at the centromere
• MEIOSIS I
  • PROPHASE I
    • Each pair of homologous chromosomes line up side by side (synapsis)
    • The homologous chromosomes are held tightly together along their lengths
    • While lined up, segments of the chromosomes may be exchanged This is what provides variation (crossing over)
    • As prophase I continues, the centrosomes move to the poles of the cell and spindle fibres form
  • METAPHASE I
    • The pairs of homologous chromosomes line up along the equator of the cell
    • The spindle fibres attach to the centromere of each homologous chromosome
  • ANAPHASE I
    • The homologous chromosomes separate and move to opposite poles of the cell
    • A single chromosome from each pair moves to each pole of the cell
    • The chromosome number is reduced from diploid to haploid
  • TELOPHASE I
    • Homologous chromosomes begin to uncoil and the spindle fibers disappear
    • Cytokinesis takes place, a nuclear membrane forms around each group of homologous chromosomes and two cells form (they are both haploid)
• MEIOSIS II
  • Very similar to mitosis
    • The key difference is that the cell undergoes division during meiosis II is haploid instead of diploid
    • PROPHASE II - DNA is not copied
• In sum…
  • Meiosis I
    • Copy chromosomes
    • Line up homologous chromosomes
    • Crossing over between homologous chromosomes
  • Meiosis II
    • Sister chromatids line up and seperate
    • Normal cell division (mitosis) without copying chromosomes

1.3 - Beyond Meiosis

• Identical Twins
  • Following fertilization of one egg by a sperm cell: The zygote divides into two identical cells via mitosis (same DNA=identical twins).
  • Offspring will both be male or both be female.
• Fraternal Twins
  • Two eggs are released, each fertilized by different sperm cells.
  • Two zygotes develop (different DNA= fraternal twins).
  • Offspring can be same or different sex.
• Errors during Meiosis
  • Non-disjunction: Incorrect separation of chromosomes during gamete production.
  • Results in gametes with too many or too few chromosomes.
• Error during Anaphase I
  • Homologous chromosomes fail to separate, leading to gametes with extra or fewer chromosomes.
• Error during Anaphase II
  • Sister chromatids fail to separate correctly, leading to gametes with an abnormal number of chromosomes.
• Chromosomal Abnormalities Resulting from Non-disjunction
  • Trisomy 13 (Patau Syndrome)
  • Trisomy 18 (Edward Syndrome)
  • Trisomy 21 (Down Syndrome) *Both Male or Female can be affected.
  • XXY (Klinefelter Syndrome - male -extra X)
  • XYY (Jacobs Syndrome - male - extra Y)
  • XXX (Triple X Syndrome - female - extra X)
  • XO (Turner Syndrome - female - missing X)
• Genetic Technologies
  • Karyotype: Detects chromosome abnormalities.
  • Genetic testing: Identifies gene mutations and variations by examining DNA.
  • In vitro fertilization (IVF): Eggs are fertilized by sperm outside the body and then implanted.
  • Gene cloning: Creates gene copies in foreign cells (often bacteria) to produce proteins or aid in research.
  • Cloning:
    • Reproductive: duplicates cell to create duplicate organisms
    • Therapeutic: to treat illnesses by making tissues and organs
  • Transgenic Organisms
    • Creation of organisms with DNA from different organisms.

1.4 - Trait Inheritance

• Gregor Mendel: Father of Genetics
• Types of Alleles
  • Dominant: Expressed even with one copy (uppercase letter).
  • Recessive: Expressed only with two copies (lowercase letter).
• Genotype and Phenotype
  • Genotype (Code): Allele combination for a trait.
  • Phenotype (Actual Trait): Observable trait.
  • Homozygous dominant: Two dominant alleles (e.g., YY).
  • Heterozygous: One dominant and one recessive allele (e.g., Yy).
  • Homozygous recessive: Two recessive alleles (e.g., yy).

1.5 - Intro to Hybrid Cross

• Hybrid Cross
  • Determines the probability of inheriting genetic traits.
• Steps:
  • Write Let Statements.
  • State the genotypes of the P generation.
  • Complete a Punnett Square.
  • Find out the genotype ratio and the phenotype ratio of the F1 generation.

1.6 - Codominance and Incomplete Dominance

• Codominance
  • Both alleles are fully expressed in a heterozygous genotype.
  • Examples: Animal fur with multiple colors, flower petals with multiple colors.
  • Allele Rule: Use letter with uppercase superscript (e.g., $C^W$ ).
• Incomplete Dominance
  • Neither allele is fully expressed in a heterozygous genotype, resulting in an intermediate phenotype.
  • Reason: The recessive allele is not completely concealed by the dominant allele.
  • Example: Red flower x white flower → pink flower.
  • Allele Rule: Use uppercase superscript (e.g., $C^R$ ).

1.7 - Dihybrid Cross

• Dihybrid Cross
  • Studies inheritance probabilities for two traits simultaneously.

1.8 - Special Cases of Inheritance

• Linked Genes
  • Traits located close together on a chromosome are often inherited together.
  • The chromosome segment codes for two traits.
• Blood Type Alleles
  • $I^A I^A$ or $I^A i$ = Blood Type A
  • $I^B I^B$ or $I^B i$ = Blood Type B
  • $I^A I^B$ = Blood Type AB (codominance)
  • $ii$ = Blood Type O (no antigens)

1.9 - Pedigree Analysis

• Pedigrees are diagrams that track phenotypes (traits) in a family; used to determine pattern of inheritance and genotypes

2.1 - DEVELOPMENT OF THE THEORY OF EVOLUTION

• Introduction to Evolution
  • Evolution: gradual process of change in heredity over a long period of time
• Scientific Approaches:
  • Past: evidence of biodiversity in fossils
  • Present: observing biodiversity changes in real time
  • Future: predicting upcoming biodiversity changes
• Theory vs. Law
  • Scientific Theory:
    • Based on a hypothesis / Explains why/how something happens / Can collect evidence for support to improve the theory
  • Scientific Law
    • Based on a hypothesis / Explains what will happen in a given situation / Will produce the same results after repeated testing
• People… Galápagos Islands: Darwin’s Finches
  • Learned that the finches he observed were actually different species!
  • Different beak shapes:
    • One type of beak shape will be favoured on each island due to the type of food available
    • New species will evolve overtime to help them survive the island’s habitat
• The Theory of Evolution
  • A “founder” species of finch travelled to one of the 13 islands of the Galapagos
  • Genetics
    • Over a long time: alleles for different beak shapes will be inherited over generations.
• Evolutionary Fitness
  • Fitness: How well a specific phenotype of an individual can survive and reproduce
  • Example: A finch has better fitness if:
    • It has a beak shape that helps it survive by eating the food found on the island AND it passes on its genes for beak shape to future generations by reproduction with a mate

2.2 - Evidence of Evolution

• Types of Evidence
  • Fossils
    • Fossils found in younger layers of rock more closely resemble living species
    • Not all organisms appear at the same time
    • Fossils appear in chronological order
      • Transitional Fossils:
        • Fossils that show intermediary links between groups of organisms
        • Traits from both ancestral (older) species and descendant (newer) species
  • Comparative Anatomy
    • Vestigial Structures: structures that have a reduced version of an ancestral structure – no longer has a purpose!
    • Homologous Structures: same/similar structure but different functions (common ancestor/origin)
    • Analogous Structures: similar function (but evolved separately) and have different structures and origins
  • Embryology
    • The study of early, pre-birth stages of an organism’s development
  • DNA
    • All living things share:
      • The same genetic material - DNA
      • The same, or highly similar, genetic codes
      • The same basic process of gene expression
    • Comparing gene sequences can tell us about evolutionary relationships and relatedness
    • Scientists can estimate how long ago two species diverged by counting DNA differences More differences = more evolutionary time since species split
  • Biogeography
    • Animals geographically close to each other, but in different types of environments, are more likely to be closely related than animals far from each other, but similar environments
    • The study of the past and present geographical distribution of species populations Australia, Hawaii, New Zealand
    • No large/complex terrestrial mammals (eg. wolves, bears, horses, lions, etc.)
    • Lots of small mammals (eg. koalas)
    • Lots of totally unique plant, bird, and insect species
    • Animals found on islands often closely resemble animals found on the closest continent (mainland)
    • Fossils of the same species have been found on the coast of Brazil and the west coast of Africa

2.3 - Adaptations & Mechanisms of Evolution

• Variation & Adaptation
  • Variation: genetic differences between individuals in a population; different traits
  • Adaptation: a variation that increases chance of survival Structural (physical features), Behavioural (way it behaves), Physiological (internal or cellular features)
  • Note: In new circumstances, what were once variations can be considered adaptations
• Mechanisms of Evolution: Part 1 4 Mechanisms
  • Natural Selection (4 types)
  • Genetic Mutation
  • Gene Flow (Migration)
  • Genetic Drift (2 types)
  • Change in allele frequencies over a long time.
• Selective Pressures
  • Environmental factors that influence which phenotypes are advantageous for survival and reproduction in a population
    • Predators, Competition, Climate, Disease, Resource availability (e.g., food)
• Natural Selection Requires:
  • Variation: individuals in a population differ from one another
  • Heritability: traits are passed down
  • Overproduction: more offspring produced than can survive
  • Reproductive Advantage: some survive and reproduce more
• Natural Selection: 4 Types
  • Stabilizing Selection (most common type)
    • Favours the intermediate variation over the extreme
    • FOR moderate traits
    • AGAINST both extremes
  • Directional Selection
    • Favours a particular extreme variation
    • FOR one extreme trait
    • AGAINST the other extreme trait
  • Disruptive Selection
    • Favours both extremes over the intermediate
    • FOR both extremes
    • AGAINST moderate trait
  • Sexual Selection: Non-random Mating
    • Competition for mating based on competition between males and choices made by females
    • Favours any trait that influences the mating success of an individual
• Mechanisms of Evolution: Part 2 Genetic Mutation
  • A random change in a DNA sequence.
• Example:
  • A finch gets a random mutation in its genes to have a bigger beak, helping it adapt to eat seeds on the island. better access to food → better survival → chance to reproduce →increased fitness → pass the mutation as an inherited trait to future generations
  • Can result from errors in DNA replication during cell division – creates a permanent change to that gene’s DNA sequence Gene Flow: Migration
  • The migration of individuals (and alleles) to a new environment, bringing their unique alleles for certain traits.
• Increases genetic diversity!
  • Seed & pollen distribution by wind & insect / Migration of animals / Reduces differences between populations Genetic Drift
  • A random population change that makes certain alleles pass down from one generation to the next due to chance.
• Loss of genetic diversity & inbreeding can limit the ability for the species to survive * Bottleneck effect: Some factors (disaster) reduce population to small number – then population recovers & expands * Founder effect: A few individuals start a new isolated population * Concerns: * Bottlenecking & conservation biology of endangered species * loss of alleles from gene pool / reduces variation / reduces adaptability Remember: Natural selection Differential survival & reproduction due to changing environmental conditions * climate change / food source availability / predators, parasites, diseases / toxins * combinations of alleles that provide “fitness” increase in the population * adaptive evolutionary change
  • Mutation is the only type that introduces genetic variation.

2.4 - Human Impacts on Evolution

• How Do Humans Influence Evolution?
  • Humans have become a selective force shaping evolution
  • Unlike natural selection, human-driven evolution can be intentional or unintentional
    • Artificial Selection / Habitat Destruction/Loss / Pollution & Climate Change / Overhunting
  • Artificial Selection
    • A selective pressure where humans select certain traits in order to improve or modify favourable traits
    • Selective Breeding
    • Examples: dogs, vegetables, etc. Monoculture
    • Growing only one type of a crop at one time on a specific field
    • Pros: easier to manage, specialized production (increases profits and reduces costs), higher yields
    • Cons: pest management (higher pesticide use), soil degradation (higher use of fertilizer), higher water use, decreased diversity

2.5 - Speciation

• Species: a group of living organisms consisting of similar individuals capable of producing viable offspring
• Speciation: the formation of new distinct species over the course of evolution
• What Makes a Species, a Species?
  • If two individuals can successfully mate and produce offspring that are also able to reproduce, they are considered to belong to the same species.
• Speed of Evolutionary Change
  • Gradualism
    • Slow, continuous change over time / Can be seen in transitional fossils (eg. horse evolution) / Eg. intelligence
  • Punctuated Equilibrium
    • Long periods of no change, then sudden change (eg. natural disaster, environmental shifts), more rapid
• How Do Species Actually Form? 3 STEPS
• Isolation: population is isolated
  • Allopatric Speciation Physical separation
  • Adaptive Radiation: a form of allopatric speciation / Common ancestral species evolves into differently adapted species relatively rapid / Common in island chains Isolated / Numerous habitats & resources
  • Sympatric Speciation No physical barrier
  • Divergence: separated populations’ traits diverge Species share a common ancestor but evolve to be different because of different conditions
  • Reproductive Isolation: separated populations no longer reproduce

UNIT 3: ANIMALS STRUCTURE & FUNCTION

• STRESS & THE NERVOUS SYSTEM
  • What is stress? Stress is your body’s natural response to changes, pressure, or demands
• EUSTRESS
  • “Good” stress / Helps you stay motivated, focused, and perform better / Leads to growth!
  • DISTRESS: “Bad” stress / Overwhelming or threatening / Negative effect on health There is an optimal amount of stress
  • The Nervous System: The nervous system acts as the body's central control center and communication network, enabling us to move, think, feel, and react to our surroundings Made up of the brain, the spinal cord, and nerves
• Neurons
  • The nervous system uses neurons (nerve cells) to send signals (messages) throughout the body
    • Sensory neurons: take information from your senses (what you see, touch, taste, etc.) to your brain
    • Motor neurons: take signals from your brain and spinal cord to your muscles
    • Interneurons communicate between motor and sensory neurons (eg. reflexes)
• Autonomic Nervous System
  • Controls the automatic functions of your body that you need to survive
    • Sympathetic Nervous System (SNS): “fight or flight” system; adrenaline (epinephrine)
    • Parasympathetic Nervous System (PNS): “rest and digest” system; noradrenaline (norepinephrine)
    • Enteric Nervous System: manages how your body digests food
    • Duration of Stress:
      • ACUTE
        • Short-term reaction to immediate challenges
        • Can be beneficial or harmful
      • EPISODIC
        • Frequent episodes of acute stress
        • Can develop into chronic stress
      • CHRONIC
        • Long-term, prolonged feeling of pressure from ongoing challenges
        • Negatively impacts health
    • THE RESPIRATORY SYSTEM
      • The body’s system responsible for breathing
        • Gas exchange (O2 in, CO2 out!) / Warms & adds moisture to the air you breathe in
    • The Physiological Sigh
      • A physiological sigh is a type of deep breath that can help you quickly relax: two quick inhales through the nose, followed by a slow exhale through the mouth
        • Why do it?
          • Helps quickly put you in a more parasympathetic (relaxed) state / Improves gas exchange in the lungs: releases excess CO2 that might build up / Helps us regulate our emotions and manage stress and anxiety
• Function of the Respiratory System
  • Main Functions:
    • Protects your body from particles you breathe in / Allows you to talk / Helps you smell / Balances level of acidity in your body
    • Why do we need respiration? We need oxygen to survive!
      • 17,000 – 29,000 breaths a day Plant and animals cells need oxygen to survive
      • Air is a mixture of gases:
        • Nitrogen (78%), Oxygen (21%), Argon (1%), Carbon dioxide (0.04%)
    • Respiratory Surfaces: 2 requirements for respiratory surfaces: They must be large enough for gas exchange to occur Quick enough to meet body’s needs They must be moist so gases can dissolve 4 types of respiratory surfaces: outer skin, gills, tracheal system, lungs
      • Outer Skin:
        • Entire outer skin is used for gas exchange Diffusion transports oxygen (O2) and carbon dioxide (CO2) in and out of the cells from blood Organism needs to live in moist environment Eg. the soil
      • Gills:
        • Extensions or folds in the body that increase surface area Diffusion transports gases to blood and cells All gill breathers live in aquatic environments
      • Aquatic Gas Exchange
        • Exchange gas by taking water into the mouth and ventilating it over the gills O2 in water diffuses into the blood in gills At the same time… CO2 diffuses out of the blood, across the gills, and into the water
      • Tracheal System
        • Insects use a tracheal system for gas exchange
          • Tracheae: internal system of branching respiratory tubes They connect cells directly to the environment Blood is not required
      • Lungs
        • Most land animals use lungs since they can provide more gas exchange Lungs contain sacs lined with a moist surface (epithelium)
          • Blood transports gases to cells by diffusion
    • UPPER RESPIRATORY TRACT: Nose, nasal cavity, oral cavity, pharynx, epiglottis, larynx You inhale and air enters the…
• Nasal Cavity:
  • warms and moistens air from outside before it enters the lungs / prevents damage to the thin, delicate tissue of your lungs / Nasal cavity is lined with hairs (cilia) and mucus to filter out and trap any airborne particles
  • Air then travels into…
• Pharynx:
  • the membrane-lined cavity behind the nose and mouth, connecting them to the esophagus Epiglottis: a flap that acts as a switch between the larynx and the esophagus / Permits air to enter the trachea to the lungs and food to pass into the esophagus
• Air then moves into…
  • Larynx: voicebox, made of cartilage and used for sound production in mammals
  • GAS EXCHANGE & VENTILATION LOWER RESPIRATORY TRACT: Lungs:
    • Provide the respiratory membrane, large surface area and supply of blood required for diffusion They are contained within your thoracic cavity and are protected by your rib cage (Diaphragm: dome-shaped muscle that helps you inhale and exhale)
    • Trachea: hollow tube that allows air to pass from the pharynx into the lungs Has c-shaped rings of cartilage around it to keep it semi-rigid and open Lined with mucus producing cells and cilia which protect the lungs from foreign matter
    • Bronchi: The trachea branches into two bronchi (singular = bronchus) The bronchi then branch off into smaller tubes called the bronchioles These tubes end in small sacs called the alveoli
    • Alveoli: made of warm, moist and extremely thin membrane allows for easy diffusion of gases across the membrane and into the blood each alveolus is tiny, and is surrounded by a bed of even tinier capillaries large number of alveoli allow for maximum surface area for gas exchange.
      • Transporting Gases Hemoglobin → a protein in red blood cells
        • Hemoglobin binds with oxygen from the lungs and transports it to the body’s tissues. There, the hemoglobin releases enough oxygen to meet the needs of the cells. When CO2 leaves the cells, it also enters the blood. Some is carried by hemoglobin, most is carried in the blood fluids.
          • Oxygen diffuses from the air into the red blood cells (RBCs), Carbon dioxide diffuses from RBCs to lungs where it’s exhaled from body Diffusion: Gas moves from an area of high concentration to an area of low concentration
    • Gas Exchange in Humans: Humans and most other land mammals require a lot of oxygen Require specialized organ system → Lungs
      • Gas exchanges occurs in 2 areas:
        • Lungs (external respiration)
        • External Respiration: exchange of O2 and CO2 between lungs and blood Tissues (Body’s cells) (internal respiration)
        • Internal Respiration: exchange of oxygen and carbon dioxide between blood and tissues
          • Oxygen diffuses from RBCs to cells in tissues and Carbon dioxide diffuses from tissues to RBCs where it is transported to lungs
            • Ventilation (Breathing): process of moving the oxygen-rich air to the lungs and the carbon dioxide rich air away from the lungs Process is based on air pressure in the lungs compared to atmospheric pressure → move from area of high pressure to area of low pressure
              • Ventilation: Mechanics of Breathing: 2 sets of structures responsible:
                • The muscular diaphragm - sheet of muscle that separates the thoracic cavity from the abdominal cavity Intercostal muscles (rib muscles), external intercostals and Internal intercostals
                  • Mechanics of Breathing: Inhalation The diaphragm contracts which shortens and flattens the muscle At the same time, your external intercostal muscles between each rib contract which pulls the rib cage up and out
                    • These processes act to increase the volume of the thoracic cavity, which decreases pressure and causes air to rush in
                      • Mechanics of Breathing: Exhalation The diaphragm relaxes which lengthens and raises the muscle At the same time, your internal intercostal muscle between each rib contract which pulls the rib cage in and down All these processes act to decrease the volume and increase the pressure of the thoracic cavity, thus pushing out the air
      • Lung Volumes Basic measurements of air during breathing:
        • Tidal Volume (VT): The amount of air you breathe in or out during a normal, relaxed breath
        • Inspiratory Reserve Volume (IRV): The extra air you can forcefully breathe in after a normal inhalation. Expiratory Reserve Volume (ERV): The extra air you can forcefully breathe out after a normal exhalation. Residual Volume (RV): The air that stays in your lungs after you forcefully breathe out as much as you possibly can.
      • Lung Capacities combinations of volumes
        • Vital Capacity (VC): The total amount of air you can breathe in and out forcefully (TV + IRV + ERV)
        • Inspiratory Capacity (IC): The total amount of air you can breathe in after a normal exhale (TV + IRV) Functional Residual Capacity (FRC): The amount of air left in your lungs after a normal exhale (ERV + RV)
        • Total Lung Capacity (TLC): The total volume of air your lungs can hold (TV + IRV + ERV + RV)
  • VAPING: What Vaping is: When heated, an aerosol that looks like water vapor is created that can be inhaled through the mouth into the lungs and absorbed into the bloodstream. Difference Between Smoking and Vaping: Vaping and smoking both involve inhaling nicotine and other substances into your lungs. Vapes heat liquid to make an aerosol; cigarettes burn tobacco, which creates smoke. Nicotine: a highly addictive substance extracted from tobacco leaves
    • E-liquids and flavorings sometimes have other ingredients, including:
      • Chemicals that can cause cancer (carcinogens), like acetaldehyde and formaldehyde. Chemicals known to cause lung disease, such as acrolein, diacetyl and diethylene glycol. THC (tetrahydrocannabinol), the chemical in marijuana that gets you “high.” Vitamin E acetate, linked to lung injury caused by vaping (EVALI). Heavy metals like nickel, tin, lead and cadmium. Tiny (ultrafine) particles that can get deep into your lungs.
        • What Can Vaping Do to Your Respiratory System?
          • Bronchi
            • Irritation and inflammation of the lining (feels like a sore throat or chest tightness), Increased mucus production (more coughing), Damage or slow down cilia (mucus builds up instead of being cleared properly), Risk of chronic bronchitis symptoms (persistent cough, wheezing), May trigger asthma symptoms or make them worse
              • Bronchioles:
                • Swelling and narrowing of the bronchioles (harder for air to flow in and out), Chemical exposure can cause cell damage or even scarring of the tissue, Linked to rare but serious conditions like bronchiolitis obliterans (“popcorn lung”), Increased airway resistance making breathing feel more difficult
                  • Alveoli:
                    • Inflammation makes the alveolar walls thicker (harder for oxygen and CO₂ to diffuse) Damage to alveolar cells can reduce lung elasticity and gas exchange efficiency Fluid or white blood cells can collect in alveoli during EVALI making it very hard to breathe Long-term damage can lead to scarring, reducing lung capacity
                      • Pleural Effusion: build up of too much fluid between the layers of the pleura around the lungs Chest pain Shortness of breath Inability to breathe easily unless sitting/standing upright
                • Nicotine: Nicotine is a highly addictive stimulant
                  • A person can become addicted to nicotine after just one or two uses
                    • Nicotine quickly changes brain chemistry and leaves the brain craving more
          • Nicotine Addiction
            • Nicotine causes a release of dopamine (a pleasure chemical) to give temporary feeling of pleasure The problem is… the brain then produces less dopamine expecting to get it from nicotine. In turn, a person struggles to have natural feelings of pleasure and needs nicotine to feel “normal”. Once the brain goes without nicotine and the level of nicotine drops quickly, the body has a strong craving for nicotine. This causes a slight panic state that makes logical decision making more difficult. Finding nicotine becomes the body’s top priority. Additionally, nicotine can cause a faster heartbeat and activate your “fight or flight” response quicker than normal. Nicotine in Teens: Especially susceptible to nicotine’s negative effects (can disrupt the development of brain circuits that control attention, learning, impulse control, mood, and reward sensitivity) Affects memory and concentration Can become dependent on nicotine more rapidly than adults Can increase the risk of developing mood and anxiety disorders in later life
• Functions of the Circulatory System
  • Multicellular organisms are organized into tissues and organs that require nutrients and oxygen in order to function. A transport system is necessary to perform the following:
    • transport gases, nutrients, and waste regulate internal temperature and transport chemical substances around the body protect against blood loss from injury and against diseases and toxic substances
      • 2 Types of Circulatory Systems Open: Fluid flows freely within the body cavity and makes direct contact with organs and tissues
        • The heart pumps hemolymph through a single tubular vessel into the body cavity The fluid enters the vessel through small pores called ostia.
          • Examples: insects, crustaceans Closed: Blood is kept physically contained within vessels Blood follows a continuous fixed path of circulation Confined to a network of vessels that keeps blood separate
            • Examples: earthworms, birds, humans Major Components of the Circulatory System
              • The circulatory system has three main components:
                • HEART Muscular organ that pumps blood through the body BLOOD VESSELS System of hollow tubes through which blood moves BLOOD Fluid that transports nutrients, oxygen, carbon dioxide, and many other materials *Fluid Portion. Called plasma, it consists of water and dissolved gases, proteins, sugars, vitamins, minerals, and waste products
                  • Solid Portion Called the formed portion, it consists of red blood cells, white blood cells, and platelets that are formed in