SNC2D Exam Review Notes

Cell Biology

• Cell Theory:
  • All living organisms are made of one or more cells.
  • The cell is the basic organizational unit of life.
  • All cells come from pre-existing cells.
  • Plant cells contain chloroplasts
• Cell Structures and Functions:
  • All cells contain cytoplasm, nucleic acid, and a membrane.
  • Cells vary in size and shape.
  • Vacuole: Stores cellular waste.
  • Gene: Directs protein production.
  • Chromosome: Coiled structure made mostly of DNA; a collection of genes.
• Cell Division:
  • In cell division, two identical cells are formed.
  • Multicellular organisms grow through cell division.
  • Single-celled organisms reproduce through cell division.
  • Multicellular organisms replace lost or damaged cells through cell division.
  • Mitosis:
    • Anaphase: Replicated chromosomes separate.
• Cell Membrane:
  • Materials cross the cell membrane through diffusion and osmosis.
• Tissues:
  • A tissue is a group of similar cells working together in the body.
  • Muscle Tissue:
    • Smooth Muscle: Found in the walls of the stomach and esophagus.
  • Connective Tissue: Fat is made up of connective tissue.
• Stem Cells:
  • Pluripotent Stem Cells: Can become any type of animal cell.
  • Adult stem cells: Limited to what type of cell they can become.
• Cell Differentiation:
  • The process by which cells develop from similar cells into cells that have specific functions within a multicellular organism; also known as cell specialization.
• Cell Cycle Checkpoints:
  • Purpose is to send damaged cells to their death.
  • Signals repair of cells must occur.
• Genetic Disorders:
  • Testing for the presence of genetic disorders is called DNA screening.

Organisms

• Amphibian Hearts:
  • Have a 3-chambered heart with two atria and one ventricle.
• Gas Exchange in Humans:
  • Takes place in the alveoli.

Chemistry

• Valence Electrons:
  • Calcium has 2 valence electrons.
• Ions:
  • A positive ion is called a cation.
• Metals with Multiple Charges:
  • Silver (Ag) does not have more than one possible charge.
• Nomenclature:
  • PbSe is Lead (II) Selenide.
  • Al2(CO3)_3: The ratio of aluminum ions to carbonate ions is 2:3.
  • Calcium nitrate is Ca(NO3)2.
  • IBr3 is Iodine tribromide.
• Prefixes:
  • Hexa corresponds to 6, not 7.
    • Penta - 5
    • Di - 2
    • Tri - 3
    • Tetra - 4
• Chemical Bonds:
  • Electrons are transferred in an ionic bond between atoms of a metal and a non-metal.
• Chemical Formulas:
  • 3MgCl2 contains 3 magnesium atoms and 6 chlorine atoms.
• Evidence of Chemical Change:
  • A change in color.
  • Formation of a new gas.
  • Formation of a precipitate.
  • The dissolving of a solid reactant in the solvent implies there is no chemical change
• Decomposition Reaction:
  • General equation: AB → A + B
• Single Displacement Reaction:
  • If the products are Cl2 and MgF2, the original reactants are F2 and MgCl2.
• Acids:
  • An oxyacid contains oxygen like HClO_3.
  • HBr is Hydrobromic acid.
• pH Scale:
  • A solution at pH 8 is basic.
  • A solution at pH 0 is very acidic
  • A solution at pH 10 is basic
  • A solution at pH 5 is acidic
• pH and Hydrogen Ion Concentration:
  • A solution at pH 3 has 100 times higher concentration of hydrogen ions than a solution at pH 5.
• Neutralization Reaction:
  • An acid and a base react to form a salt and water.
• Law of Conservation of Mass:
  * Mass of reactants should equal mass of products

Environmental Science

• Greenhouse Gases:
  • Building up in the atmosphere.
• Anthropogenic Factors Affecting Climate Change:
  • The burning of fossil fuels.
• Ocean Conveyer Belt:
  • The deep current is colder and saltier than the surface current.
• Forcing Agents on Global Temperature:
  • CO2 has the greatest impact.

Optics

• Angle of Reflection:
  • The angle between the normal and the reflected ray.
• Incident Ray:
  • A ray of light that travels toward a surface.
• Transmission of Light:
  • In the form of electromagnetic waves.
  • In straight lines.
  • As energy.
• Light Density:
  • If light passing from one medium to another bends, the mediums have different densities.
• Speed of Light in a Vacuum:
  • 3.0 x 10^8 m/s
• Snell's Law:
  * n1sin\theta1 = n2sin\theta2

True/False

• The endoplasmic reticulum is NOT responsible for the production of usable energy in a cell (False).
• A gene carries the instructions to make a specific protein (True).
• DNA replication does NOT occur during the G1 phase of the cell cycle (False). It occurs during S phase.
• Na+ has the same electronic structure as Ne (True).
• Melting snow is NOT an example of a chemical change (False). It is a physical change.
• An oxyacid is a compound containing hydrogen and one other element (False).
• Blood is NOT made up of predominantly white blood cells and platelets (False). Blood is composed of red blood cells, white blood cells, platelets, and plasma.

Matching

• Carcinogen - E. Cancer-causing agent
• Cartilage - I. Connective tissue that provides support
• Mitosis - A. Process of cell division
• Synthesis Reaction - D. Involves the combination of smaller atoms/molecules
• Flammability - J. Chemical property
• Negative Feedback - G. Global warming, ↑ volcanic activity, causing cooling
• Visible Light - B. Part of the Electromagnetic Spectrum
• Multivalent Ion - C. More than one possible charge
• Cation - F. Positive Ion

Short Answer

• Diffusion:
  • Diffusion is the process involved in the exchange of gases in organisms.
  • It is the movement of molecules from an area of higher concentration to an area of lower concentration.
  • Examples:
    • Worm: Oxygen diffuses across their moist skin.
    • Frog: Gas exchange occurs through their skin and lungs via diffusion.
    • Human: Oxygen diffuses from the alveoli in the lungs into the blood, and carbon dioxide diffuses from the blood into the alveoli.
• Stem Cells:
  • Stem cells are undifferentiated cells that can differentiate into specialized cells.
  • Pluripotent Stem Cells: Can become any type of animal cell.
  • Adult Stem Cells: More limited in their differentiation potential.
• Effects of Global Warming on Human Health:
  • Increased heat waves and heat-related illnesses.
  • Spread of infectious diseases due to changing climate patterns.
  • Air pollution and respiratory illnesses.
  • Food and water insecurity due to disrupted agricultural practices.
• Positive Feedback:
  • Positive feedback is a process where the effects of an initial change are amplified, leading to further changes in the same direction.
  • Example: As global temperatures rise, ice melts, reducing the Earth's albedo (reflectivity). This causes more solar radiation to be absorbed, leading to further warming and more ice melt.
• Goldilocks Phenomenon:
  • The Goldilocks phenomenon refers to the idea that Earth's conditions are "just right" for life.
  • It's the perfect distance from the sun, has water, and has oxygen/ozone layer to support life.
  • It is important because it allows for the existence and evolution of life as we know it.
• Factors Influencing Global Warming:
  • Human Factors:
    • Burning of Fossil Fuels: Releases greenhouse gases like CO2 into the atmosphere, trapping heat.
    • Deforestation: Reduces the number of trees available to absorb CO2, increasing its concentration in the atmosphere.
  • Natural Factors:
    • Volcanic Activity: Volcanic eruptions release gases and particles into the atmosphere, which can have both warming and cooling effects.
    • Changes in Solar Activity: Fluctuations in the sun's energy output can affect Earth's temperature.
• Wavelength Calculation:
  • Given: Frequency (f) = 5.00 × 10^{14} Hz, Speed of light (c) = 3.00 × 10^8 m/s
  • Formula: \lambda = c/f
  • \lambda = (3.00 × 10^8 m/s) / (5.00 × 10^{14} Hz) = 6.00 × 10^{-7} m
  • Conversion to nanometers: 6.00 × 10^{-7} m × (10^9 nm / 1 m) = 600 nm
• Speed of Light in a Medium:
  • Given: Index of refraction (n) = 2.50, Speed of light in a vacuum (c) = 3.00 × 10^8 m/s
  • Formula: v = c/n
  • v = (3.00 × 10^8 m/s) / 2.50 = 1.20 × 10^8 m/s
• Refraction of Light:
  • Since the light is bending away from the normal, Liquid A has a high density.
  • The speed of light decreases in a high density
• Snell's Law Application:
  • Given: \theta1 = 35°, n1 = 1.00, n_2 = 1.50
  • Formula: n1sin\theta1 = n2sin\theta2
    • (1.00)sin(35°) = (1.50)sin(\theta_2)
    • sin(\theta_2) = (1.00 × 0.5736) / 1.50 = 0.3824
    • \theta_2 = sin^{-1}(0.3824) = 22.5°
  • As light enters the glass, its speed decreases. The higher the refractive index, the slower the speed of light. Furthermore, frequency does not change, but wavelength decreases.

Chemical Reactions

• Synthesis:

  • A + B \rightarrow AB

• Decomposition:

  • A B \rightarrow A + B

• Single Displacement:

  • A + BC \rightarrow AC + B

• Double Displacement:

  • AB + CD \rightarrow AD + CB

• Hydrochloric Acid and Sodium Hydroxide:

  • Word Equation: Hydrochloric acid + Sodium hydroxide → Sodium chloride + Water
  • Balanced Equation: HCl + NaOH \rightarrow NaCl + H_2O
  • Type of Reaction: Neutralization (Acid-Base)
  • Law of Conservation of Mass: Mass is neither created nor destroyed in a chemical reaction.
  • Mass of Final Product:
    • 76.457 g (reactants) = 58.442 g (NaCl) + x (water)
    • x = 76.457 g - 58.442 g = 18.015 g

• Sodium and Copper (II) Chloride

  • Products: Copper and Sodium Chloride
  • Balanced Chemical Equation: 2Na(s) + CuCl_2(aq) \rightarrow Cu(s) + 2NaCl(aq)
  • Type of Reaction: Single Displacement Reaction.