Science Exam Review Notes

Science Exam Review

Biology

Plant Tissue

• Dermal Tissue
  • Location: Outermost layer of plant organs.
  • Function: Protective barrier, controls water and gas exchange.
  • Example: Epidermal cells.
• Ground Tissue
  • Functions: Photosynthesis, structural support.
  • Role: Metabolic functions and support.
• Vascular Tissue
  • Functions: Transports water, nutrients, and sugars, provides physical support.
  • Key role: Essential for substance movement and structural support.

Human Organ Systems

• Circulatory System: Transports blood, nutrients, gases, and wastes.
• Digestive System: Takes in food, breaks it down, absorbs nutrients, removes solid waste.
• Respiratory System: Controls breathing, exchanges gases in lungs.
• Excretory System: Removes liquid wastes from the body.
• Immune System: Defends the body against infections.
• Muscular System: Works with bones to move the body.
• Endocrine System: Makes and releases hormones to keep body balanced.
• Reproductive System: Organs to produce babies.
• Integumentary System: Includes skin, hair, nails; waterproof barrier.
• Nervous System: Detects environmental changes, tells the body how to respond.
• Skeletal System: Supports and protects the body, helps muscles move.

Chemistry

Types of Charges

• Ion: A charged particle formed by loss or gain of electrons.
• Cation: Positively charged ion.
• Anion: Negatively charged ion.
• Binary Ionic Compound: Compound of metal cation and nonmetal anion.

Types of Chemical Reactions

1. Determine the ratio of positive to negative ions so total charge is zero.
2. Write the cation first, then the anion, using numbers to show the simplest ratio that balances the charges.

Decomposition Reaction

• A compound breaks down into two or more simpler compounds.

Synthesis Reaction

• Two or more reactants combine to produce a new product.
• Example: Space Shuttle Launch
  • Shuttle thrusters use the synthesis reaction: 2H₂ + O₂ → 2H₂O
• Example: Fertilizer Production
  • Ammonia (NH₃) production: N₂ + 3H₂ → 2NH₃
• Example: Electrolysis of Water
  • Splitting water into hydrogen and oxygen: 2H₂O → 2H₂ + O₂
• Example: Explosives (TNT)
  • Decomposition of TNT: 2C₇H₅N₃O₆ → 3N₂ + 5H₂O + 7CO + 7C

Catalytic Converter

• Contains platinum, palladium, and rhodium as catalysts.
• Converts toxic nitrogen oxides (NO and NO₂) into harmless nitrogen (N₂) and oxygen (O₂).
• Precious metals speed up chemical reactions.

Smog and Air Pollution

• Formation of nitrogen oxides: N₂ + O₂ → 2NO then 2NO + O₂ → 2NO₂

Making Cement and Mortar

• Decomposition: Heating calcium carbonate: CaCO₃ → CaO + CO₂
• Synthesis: CaO mixed with water to form calcium hydroxide: CaO + H₂O → Ca(OH)₂

Acids, Bases, and pH

• Acids: Compounds producing hydrogen ions (H⁺) in water.
  • Properties: Conduct electricity due to ionization, react with metals, corrosive.
  • Binary acids: Hydrogen + nonmetal (e.g., HCl).
    • Naming: hydro- + root of non-metal + -ic acid
      • Oxoacids: Contain hydrogen, oxygen, and another element
    • Naming: If the anion ends in -ate, change to -ic acid, if it ends in -ite, change to -ous acid
• Bases: Compounds producing hydroxide ions (OH⁻) in water.
  • Properties: corrosive, conduct electricity due to dissociation
  • Naming Bases: metal name + hydroxide
• Neutralization Reactions: Acid + Base → Salt + Water
  • Antacids treat excess stomach acid (HCl).
  • Acid Spill Clean-Up: Using Ca(OH)₂ (a base) to neutralize acid.
  • Liming of Lakes: Treating acidified lakes with CaCO₃ (limestone).
• pH Scale
  • Acidic: pH < 7 (e.g., lemon juice, vinegar).
  • Neutral: pH = 7 (e.g., pure water).
  • Basic (alkaline): pH > 7 (e.g., soap, bleach).
• Methods of Determining pH
  1. pH Meter: Measures pH electronically.
  2. Litmus Paper: Red turns blue in bases, blue turns red in acids.
  3. Universal Indicator: Mixture of indicators showing different colors at different pH values.

Examples of Chemical Reactions

• Corrosion and Airplane Safety:
  • Formation of rust (Fe₂O₃) weakens structure.
• Road Salt and Vehicle Damage:
  • Salt speeds up rusting process.

Climate Change

Climate Zones

• Cause: Unequal warming of Earth's surface.
• Polar regions receive less intense sunlight, are colder.
• Distance affects temperature and precipitation.

Types of Climate Zones

• Permanent Ice: Icecaps with < 50 cm precipitation; only lichens and mosses.
• Tundra: Permafrost, thin soils, few trees.
• Boreal Forest: Coniferous trees, 30-85 cm precipitation, freezing temperatures six months.
• Temperate Deciduous Forest: Eastern Canada, 75-180 cm rain, cold winters, warm summers.
• Temperate Rainforest: Coastal BC, > 200 cm rain, mild temperatures (5°C–25°C).
• Grassland: Prairies, 25-100 cm rain, hot summers, cold winters.
• Desert: Southern BC, < 25 cm rain, spiny leaves, deep roots.

Tools for Monitoring Climate

• Climograph: Climate data for regions, average precipitation and temperature.
• Satellite: Monitors climate, forecasts weather.
  • Geostationary: Orbits at same speed as Earth, monitors one area.
  • Polar Orbiting: Monitors the whole planet in 6 hours, north and south poles.

Physics

Mirrors and Lenses

• Plane mirrors: Flat reflective surface.
• Concave (converging): Reflective surface curves inward.
• Convex (diverging): Reflective surface curves outward.
• Converging lens: Brings parallel light rays to a common point.
• Diverging lens: Spreads parallel light rays away from a common point.
• Refraction: Bending of light as it passes a medium

Molecular Biology

DNA

• DNA (Deoxyribonucleic Acid): Contains genetic information, controls cell activities.
• Composed of nucleotides: Adenine (A), Thymine (T), Cytosine (C), Guanine (G).
• Chromosomes: DNA coiled into structures.
• Humans have 46 chromosomes (23 pairs).
• Genes: Segments of DNA instructing to make specific proteins.
• Proteins determine cell structure and function.
• Cell Specialization: Muscle cells contain proteins for contraction, nerve cells produce proteins for signal transmission.

Variety of Cells

• All cells contain the same DNA, but different cell types use different parts of the DNA.
• Selective gene expression creates diversity.

Mutations

• UV Radiation: Causes mutations leading to skin cancer.
• X-rays: Can break DNA strands, increasing mutation risk.
• Chemical Mutagens: Cause mutations that can lead to lung cancer.
• Inherited Mutations: Passed from parents.
• Down Syndrome: Involves abnormal chromosome number, causing developmental delays.
• Huntington Disease: Affects brain nerve cells, leading to loss of muscle control, cognitive decline.
• Phenylketonuria (PKU): Affects liver cells’ ability to process the amino acid phenylalanine, leading to harmful buildup.

Plant Biology

Parts of a Flower

• Petals: Attract pollinators.
• Stigma: Receives pollen.
• Style: Pathway for pollen.
• Stamen: Male reproductive organ.
• Ovary: Contains ovules, develops into fruit.
• Sepals: Protects flower bud.
• Pistil: Female part of flower.
• Anther: Produces pollen.
• Filament: Holds up anther.

Movement of Water in Plant

• Root Hair Cells: Absorb water through osmosis.
• Cortex: Water travels across layers of cells.
• Endodermis: Controls what enters vascular tissue.
• Xylem: Transports water up the plant.

Shoot

• Lungs: Breathing process.
  • Inhale: Air moves through nasal passages and pharynx.
  • Cilia and mucus trap particles.
  • Air enters trachea, bronchi, bronchioles, and alveoli.
  • Gas exchange in alveoli: Oxygen enters blood, carbon dioxide exits.
  • Red blood cells carry oxygen via hemoglobin.
  • Exhale: Carbon dioxide leaves the body.
  • Breathing rate increases with CO₂ buildup.

Smoking

• Damages cilia, preventing removal of foreign particles.
• Carbon monoxide and tar cause respiratory problems.

Environmental Science

El Niño and La Niña

• El Niño: Weak winds cause warm water to move eastward, preventing cold water from rising.
• La Niña: Strong winds push warm Pacific waters west, causing cold water to rise in the eastern Pacific.

Writing Chemical Formulas

• Potassium iodide: KI
• Calcium oxide: CaO
• Lithium sulfide: Li₂S
• Aluminum nitride: AlN
• Barium fluoride: BaF₂
• Iron(II) bromide: FeBr₂
• Lead(IV) sulfide: PbS₂
• Copper(II) nitrate: Cu(NO₃)₂
• Tin(IV) oxide: SnO₂
• Chromium(III) phosphide: CrP
• Magnesium sulfate: MgSO₄
• Aluminum carbonate: Al₂(CO₃)₃
• Potassium permanganate: KMnO₄
• Iron(III) hydroxide: Fe(OH)₃
• Calcium phosphate: Ca₃(PO₄)₂
• Nitrogen monoxide: NO
• Sulfur hexafluoride: SF₆
• Carbon tetrachloride: CCl₄
• Phosphorus trichloride: PCl₃
• Dinitrogen tetrahydride: N₂H₄

Balancing Chemical Equations

• Identify Reaction:
  • Mg + O₂ → MgO
  • H₂O₂ → H₂O + O₂
  • Zn + HCl → ZnCl₂ + H₂
  • Na₂CO₃ + CaCl₂ → NaCl + CaCO₃
  • CH₄ + O₂ → CO₂ + H₂O
• Balanced Equations:
  • 2 H₂ + O₂ → 2 H₂O
  • 4 Al + 3 O₂ → 2 Al₂O₃
  • 2 Fe + 3 Cl₂ → 2 FeCl₃
  • 2 NaOH + H₂SO₄ → Na₂SO₄ + 2 H₂O
  • C₃H₈ + 5 O₂ → 3 CO₂ + 4 H₂O
  • Ca + 2 H₂O → Ca(OH)₂ + H₂
• Word Equations:
  • Magnesium reacts with oxygen to form magnesium oxide.
  • Sodium reacts with chlorine gas to form sodium chloride.
  • Calcium carbonate decomposes into calcium oxide and carbon dioxide
  • Aluminum reacts with copper(II) chloride to produce aluminum chloride and copper.
  • Methane burns in oxygen to form carbon dioxide and water.

Leaf Structure and Function

• Function: Provide large surface area for photosynthesis.
• Upper Surface: Epidermis with waxy cuticle to reduce water loss.
  • Epidermal cells allow sunlight to pass through.
• Mesophyll Tissue: Palisade and spongy cells.
  • Palisade cells: Main photosynthesis site, packed with chloroplasts and mitochondria.
  • Spongy parenchyma cells: Loosely packed for gas exchange.
• Vascular Bundles (Veins): Xylem and phloem.
  • Xylem: Delivers water.
  • Phloem: Transports sugars.
• Lower Leaf Surface: Epidermis with guard cells and stomata.
  • Stomata: (CO₂) enters for photosynthesis, (O₂) exits
    • Guard cells control stomata opening and closing.

Root Structure (Cross Section)

• Root hairs: Water and mineral absorption.
• Cortex: Stores starch.
• Endodermis: Controls water and mineral flow.
• Pericycle: Grows branch roots.
• Vascular tissue: Xylem and phloem.
  • Xylem: Transports water and minerals upward.
  • Phloem: Transports sugars to other parts of the plant.

Stem

• Helps plant stand upright
• Xylem Tissue:
  • Transports water and minerals from the root
  • Made of dead, hollow cells
• Phloem Tissue
  • Transports sugars from the leaves
  • Made of living cells with porous walls
• Vascular Bundles: groups of xylem and pholem vessels

Human Anatomy and Physiology

Respiratory System

• Nasal Cavity: Filters, warms, and moistens air.
• Pharynx: Passage for air and food.
• Epiglottis: Directs air to trachea, blocks food.
• Larynx: Contains vocal cords.
• Trachea: Carries air to bronchi.
• Bronchi: Two tubes carrying air into lungs.
• Bronchioles: Smaller branches controlling airflow.
• Alveoli: Tiny sacs for gas exchange.
• Epithelial Tissue: Lines airways, produces mucus, traps microbes, allows gas exchange.
• Diaphragm: Muscle controlling breathing.
• Lungs: Organs where gas exchange occurs.

Circulatory System

• Heart: Two sides pumping blood to lungs and body.
• Valves: Prevent backflow.
• Right Atrium: Receives deoxygenated blood.
• Right Ventricle: pumps deoxygenated blood to lungs.
• Lungs: Exchange oxygen and carbon dioxide.
• Left Atrium: Receives oxygenated blood.
• Left Ventricle: Oxygenated blood to body.
• Aorta: Largest artery, distributes oxygen-rich blood.
• Blood Vessels: Arteries, veins, capillaries.

Digestive System

• Mouth: Chews food, starts digestion.
• Tongue: Moves food.
• Salivary Glands: Produce saliva.
• Pharynx: Passes food to esophagus.
• Esophagus: Pushes food to stomach.
• Stomach: Mixes food, digests proteins.
• Duodenum: Main digestion site.
• Pancreas: Makes digestive enzymes.
• Liver: Produces bile.
• Gall Bladder: Stores and releases bile.
• Small Intestine: Absorbs nutrients.
• Large Intestine: Absorbs water and vitamins.
• Rectum: Stores feces.
• Anus: Eliminates waste.

Medical Technology