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.