Science Exam

Weather

Weather

Short term conditions at a specific times and areas

• Temperature

• Precipitation

• Cloud cover

• Wind speed

• Presence of Fog

Climate

The pattern of weather over a long period of time, can predict weather in the future

Earth's Tilt

Results in different parts of it to receive different amounts of solar energy during its orbit resulting in seasons.

Energy Absorbed

Any energy absorbed is thermal energy which determines temperature-(heat sinks absorb a lot thermal energy with little to difference in temperature to themselves things like large bodies of water and gases in the air)

Energy Out

Some energy is converted into to infrared radiation and some energy is reflected back into space.

Albedo

percentage of thermal energy a surface reflects. The more energy reflect the cooler the climate will be. Light colours have high percentages.

Greenhouse Effect

the capacity of certain gases in the atmosphere to trap heat, thereby warming the Earth keeping it at a livable temperature.

Evidence for Current Climate Change

• Global warming- the fast increase of Earth’s average temperature due to human activity

• Rising Sea Levels- risen over the past 120 years due to melting ice and thermal expansion

• Change in Seasons- Shorter springs and winters, longer summmers

• Change in Weather- increase in violent storms and drought

Anthropocentric Greenhouse Emissions

• Co2- burning fossil fuels, deforestation

• Methane- landfills, livestock digestions, mining (cows)

• Nitrous oxide- fertilizers, burning fossil fuels

• CFC and HFC- refrigerators

Canada Greenhouse Gases Emissions

• Industrial process.- Co2, Methane

• Transportation- Co2

• Agriculture- Methane, Nitrous Oxide

• Waste management, Methane

Impacts on Humans

Disease- disease-carrying organisms can live farther north with the increase in temperature ( Malaria, West Nile Disease, Lyme Disease)

Flooding- Rising sea levels can potentially displace hundreds of millions of people especially those in low lying costal cities

Impacts of Nature

Ocean Acidification- change in ocean’s pH due to Co2( shellfish and coral are sensitive and are affected.

Global warming- species having to move farther north to survive because they can’t apabt to how fast the weather is changing , causing risk of extinction

Pure substance

A substance that contains one kind of matter and distinct properties

Element

Can’t be broken down into any other substance by ordinary means

Compounds

Two or more element that have been chemically combined in a particular ratio

Type of Mixtures

Solution- one or more substances dissolved in another substance. They look like pure substances

Mechanical- different components of the mixture are visible

Physical Changes

Does not result in a new substance being formed

• Changes in state

• Breaking

• Creation of Mixture

Chemical Change

Results in a new substance being formed

• Change in colour

• Production of gas ( bubbles)

• Precipitate formation

• Energy being released or absorbed( light)

Ions

• Formed by either losing or gaining electrons to get a full orbital( stable).

• Metals lose electrons (+)

• Non-metals gain electrons (-)

Ionic Compounds

Positive and negative ions attract and create a fixed ratio that will balance out to zero. It will always contain a metal and a nonmetal

Molecular Compounds

Atoms share electrons that form bonds

Acids

Release H+ ions when dissolved in water

• Taste sour

• Corrosive

• Reacts with metals

• Conduct electricity when dissolved in water

• Reacts with carbonate compounds and bases

Bases and Their Properties

Release OH- ions when dissolved in water

• Conduct electricity when dissolved in water

• Feel slippery

• Taste bitter

• Reacts with acids

• Corrosive

pH

Measures how acidic or basic a solution is

• 0- >7 = acidic

• 7 = neutral

• <7- 14 = basic

Synthesis Reaction

A chemical reaction where two reactants combine to form one product .

Decomposition

A chemical reaction where one reactant is broken down into two products

Single displacement

An element displaces another element in a compound forming a new compound

Double Displacement

Elements in two compound sswitch places to create two new compounds

Combustion

hydrocarbon + oxygen burns and releases light and thermal energy

Blue- complete happens when an abundance of oxygen is available

Orange - incomplete happens when oxygen is limited

Fire Necessities

• Fuel

• Oxygen

• Thermal enegy

Fighting Fires

• Cut off fuel source

• Smother fire ( sand, fire blankets, etc )

• Cool fire down with water

Types of Neutralization Reactions

Acid-base- react to form water and a ionic compound(salt)

Acid- carbonate compound- react to form water and carbon dioxide and ionic compound

Cell Theory

1. All things are composed of one or more cells

2. The cell is the most basic unit of life

3. All cells come from preexisting cells

Prokaryotes

• No nucleus

• Smaller

• No membrane- bound organelles

  ( bacteria, archaea)

• Single celled

Eukaryotes

• Nucleus

• Larger

• Membrane-bound organelles

• single and multicellular

  (fungi, plants, animals)

Organelles in the Cell

• Nucleus - control all cell activities

• Mitochondria- converts energy using oxygen and stores it

• ER-3D branch of tubes that transport proteins through the cell

• Golgi apparatus- collect and process to be removed from the cell

• Cell membrane- allow substances to leave and enter the cell, supports cell structure

Reasons Why Cells Divide

1. Reproduction

2. Replace and Repairment

3. Growth

Interphase

Longest stage, DNA in cell duplicates in preparation for division, chromatids ( X-shaped) are formed from copied chromosomes

Mitosis

Division of nucleus, four stages

Prophase

Chromatids thicken becoming visible, membrane around nucleus starts dissolving, spindle fibres form

Metaphase

Chromosomes line up in the middle of the cell, membrane around nucleus finishes dissolving

Anaphase

Chromatids are pulled apart by spindle fibres to opposite sides of the cells ( 1 chromatid broken = 2 chromosomes)

Telophase

Chromosomes become thin again, a new membrane forms around the two groups of chromosomes

Cytokines

the cytoplasm and other organelles are distributed on two sides of the cell, membrane pinches in separating the cells

Epithelial Tissue

Tightly packed cells that line and protect organs, cavities, etc

• Skin

• Lining of red blood cells

Connective Tissue

Supports, protects, connects all body parts

• Ligaments

• Blood

• Tendons

• Cartilage

Nerve Tissue

Transmits electrical signals throughout the body, communication and coordination of body functions

• Brain,

• Spinal cord

Muscle Tissue

Responsible for movement and generating force.

• Tongue

• Biceps

• Hamstring

• Triceps

Levels of Organization ( Animal)

Cells > Tissues > Organs > Organ Systems > Organism

Respiratory System Organ Functions

1. Lungs - Main organ for gas exchange

2. Trachea - Tube connecting the throat to the lungs that air passses through

3. Bronchi - Branches of the trachea leading to each lung

4. Alveoli- Microscopic air sacs in the lung that are surrounded by capillaries that move oxygen and bring Co2)

Digestive System Organ Functions

• Mouth- breaks down food mechanically and enzymes break down carbohydrates

• Esophagus- Muscular tube that food travels down

• Stomach - Secretes digestive enzymes and acids to break down food. (proteins)

• Small Intestine - Absorbs nutrients into the bloodstream.

• Large Intestine - Absorbs water and forms feces.

• Liver - Produces bile to aid in fat digestion. Pancreas - Releases enzymes to further break down food.

• Gallbladder - Stores and releases bile.

Circulatory System Organ Functions

Heart: Four chambers, nerve cells tell upper chambers to contract pushing blood into the lower chambers, the lower chambers contract pushing blood to the rest of the body

Arteries: Carry oxygenated blood away from the heart to the body's tissues.

Veins: Carry deoxygenated blood back to the heart from the body's tissues.

Capillaries: Connect arteries and veins, allowing for the exchange of oxygen, nutrients, and waste products with body cells.

Plant Characteristics

• Multicellular

• Photosynthesize

• Anchored to the ground

• Eukaryotes

Roots

• Anchor plant in place

• Store food for plant

• Absorb water and minerals from the soil

Stem

Support structure of plant, specialized stems can have other fuctions

Flowers

Reproductive organs of plants

Leaves

creates food for plant, photosynthesize

Flowers Pollinated by Wind

• Smaller

• Less colourful

• Unscented

• Lacking nectar

Flowers Pollinated by Animals

• Larger

• Colourful

• Scented

• Filled with Nectar

Photosynthesis

carbon dioxide + water + light energy > glucose + oxygen

Happens in leaves which contain chloroplasts, chloroplasts contain thylakoids, thylakoids contain chlorophyll

Gas Exchange in Leaves

Plants collect carbon dioxide and expel oxygen using tiny opening in their cells (stomata) Those are controlled by guard cells

Incandescence

light produced by a heated object, typically due to high temperatures causing it to glow.

• Candles

• Incandescent light bulbs

Fluorescence

Light produced by a substance that has absorbed invisible UV radiation and converts it into visible light

• light bulbs

Chemiluminescence

Light produced by a chemical reaction

• Glow Sticks

Bioluminescence

Chemiluminescence in living organisms

• Firefly

• Deep Sea Fish

Primary Colors of Light ( additive colour theory)

Red, green, and blue, when mixed together they mixed together they create white light

Secondary Colours of Light ( additive colour theory)

Created by combining two primary colors of light

• Red + green = yellow

• Red + blue = magenta

• Green + blue = cyan

Complimentary Colours of Light ( additive colour theory)

Pairs of colors that, when combined, produce white light, always one primary colour and secondary

• red + cyan (green + bule) = white light

• green + magenta (red + blue) = white light

• blue + yellow ( red + green) = white light

Colours in the Eye

Rods- in the eye help distinguish objects in the dark

Cones- in the eye, three types that are sensitive to each primary colour

Pigments (subtractive colour theory)

Chemicals that absorb certain colours of light and reflect other. The color(s) that are reflected are the colour we see

• Blue coloured object will absorb red and green light and reflect blue light

• Yellow coloured object will absorb blue light and reflect green and red light

Primary and Secondary Colours of Pigments (subtractive colour theory)

Opposite of light

• P: cyan, magenta, yellow

• S: red, blue green

Reflection

The bouncing back of light off an opaque surface.

Refraction

Bending of light as it passes from one medium to another, caused by a change in its speed. It occurs due to the change in the density of the medium.

Converging Mirror

Type of mirror that curves inward, causing light rays to come together at a focal point.

Diverging Mirror

A type of mirror that curves inward, causing light rays to diverge or spread apart..

• Rearview mirrors

• Security mirrors.

Converging lens

Lens that is thickest in the center allowing light rays to come together at the focal point.

• Magnifying glasses

• Camera lenses

Diverging lens

A lens that is thinnest in the center and causes parallel rays of light to spread apart, when passing through it.

• binoculars