Science exam

Key Structures of Plant and Animal Cells

Nucleus, cell membrane, cytoplasm and mitochondria; plants also have cell walls and chloroplasts.

How are plant and animal cells the same/different?

They both have a Nucleus, cell membrane, cytoplasm and mitochondria; plants also have cell walls and chloroplasts

Definition of Tissue

A group of similar cells working together to perform a specific function.

Definition of Organ

A structure made of different tissues working together to perform a specific task.

Definition of Organ System

A group of organs working together to carry out major body functions.

Cell to Organism Hierarchy

Cells form tissues, tissues form organs, organs form organ systems, and systems form organisms.

Producer

An organism that makes its own food using sunlight.

Consumer

An organism that eats other organisms for energy.

Decomposer

An organism that breaks down dead material and wastes.

Food Chain

A linear sequence showing how energy flows from one organism to another.

Food Web

A complex network of interconnected food chains in an ecosystem.

Trophic Level

The position an organism occupies in a food chain or web.

Photosynthesis

The process by which plants use sunlight, water, and carbon dioxide to create oxygen and energy in the form of sugar.

Chloroplast

The plant cell structure where photosynthesis takes place, containing chlorophyll.

Chlorophyll

The green pigment in chloroplasts that absorbs sunlight for photosynthesis.

Equation for Photosynthesis

Carbon dioxide + Water + Sunlight -> Glucose + Oxygen

Role of Sunlight in Photosynthesis

Provides the energy needed to convert carbon dioxide and water into glucose.

example of a part of the digestive system:

Mouth

Chews food and mixes it with saliva.

Example of a part of the digestive system:

Oesophagus

Muscular tube that pushes food from the mouth to the stomach.

Example of a part of the digestive system:

Stomach

Uses acids and enzymes to break down food.

Example of a part of the digestive system:

Small Intestine

Absorbs nutrients from digested food into the bloodstream.

Example of a part of the digestive system:

Large Intestine

Absorbs water and prepares waste for elimination.

Example of a part of the digestive system:

Liver

Produces bile to help break down fats.

Example of a part of the digestive system:

Pancreas

Produces digestive enzymes to help break down food.

example of a part of the digestive system:

Gallbladder

Stores bile produced by the liver.

Process of Digestion

Food is broken down mechanically and chemically, nutrients are absorbed, and waste is eliminated.

What happens to digested food?

Nutrients are absorbed into the bloodstream in the small intestine and delivered to body cells.

Role of enzymes in digestion

They act as biological catalysts to speed up the breakdown of large food molecules into smaller, soluble ones.

Carbohydrase function

Breaks down carbohydrates into simple sugars.

Protease function

Breaks down proteins into amino acids.

Lipase function

Breaks down fats (lipids) into fatty acids and glycerol.

Destination of absorbed nutrients

Transported by the blood to cells around the body for energy, growth, and repair.

Where does digestion happen?

Throughout the digestive tract, primarily in the mouth, stomach, and small intestine.

An example of a type of tooth:

Incisors

Chisel-shaped front teeth used for biting and cutting food.

An example of a type of tooth:

Canines

Sharp, pointed teeth used for tearing food.

An example of a type of tooth:

Premolars

Teeth with flat surfaces used for chewing and grinding food.

An example of a type of tooth:

Molars

Large, flat teeth at the back of the mouth used for crushing and grinding food.

Role of teeth in digestion

Mechanically breaks down food into smaller pieces to increase surface area for chemical digestion.

Producer

Makes its own food using sunlight rather than eating other organisms.

Herbivore

An animal that eats only plants.

Carnivore

An animal that eats other animals.

Scavenger

An animal that feeds on the remains of dead animals.

Element

A pure substance made of only one type of atom.

Compound

A pure substance made of two or more different elements chemically bonded together.

Mixture

A combination of two or more substances that are not chemically bonded and can be separated physically.

States of Matter

The three main states are solid, liquid, and gas.

Melting

The process of changing state from a solid to a liquid.

Freezing

The process of changing state from a liquid to a solid.

Evaporation and Boiling

The processes of changing state from a liquid to a gas.

Condensation

The process of changing state from a gas to a liquid.

Sublimation

The process of changing state directly from a solid to a gas.

Solid particles

Closely packed in a regular pattern, vibrating in fixed positions.

Liquid particles

Close together but random, able to slide past each other.

Gas particles

Far apart and random, moving quickly in all directions.

Solution

A mixture where a solute is completely dissolved in a solvent, forming a clear mixture.

Suspension

A mixture containing small solid particles that do not dissolve and will settle out over time.

Methods to separate mixtures

Filtration, evaporation, distillation, chromatography, and magnetism.

Solubility

A measure of how much solute can dissolve in a given amount of solvent at a specific temperature.

Physical Change

A change where no new substances are formed, such as changes of state or dissolving.

Chemical Change

A change where one or more new substances are formed with different properties.

Structure of the Atom

Consists of a central nucleus containing protons and neutrons, surrounded by electrons.

Atoms vs Molecules

An atom is a single particle, while a molecule is two or more atoms chemically bonded together.

Atomic Number

The number of protons in the nucleus of an atom.

Mass Number

The total number of protons and neutrons in the nucleus of an atom.

Finding Neutrons in an Atom

Subtract the atomic number from the mass number.

Counting atoms from a chemical formula

Add up the subscripts for each element; for example, NaCl contains 2 atoms.

Test for Hydrogen gas

A lighted splint produces a characteristic 'squeaky pop' sound.

Test for Carbon Dioxide gas

Turns limewater milky or cloudy when bubbled through it.

Test for Oxygen gas

A glowing splint relights when placed in the gas.

Reactants

The starting substances in a chemical reaction, written on the left side of a word equation.

Products

The new substances formed in a chemical reaction, written on the right side of a word equation.

Pyroclastic flow

A fast-moving current of hot gas and volcanic matter that flows away from a volcano.

Movement of Sun, Earth, and Moon

The Earth orbits the Sun, the Moon orbits the Earth, and all three move through space as part of the solar system.

Cause of a Day

One complete rotation of the Earth on its axis, taking approximately 24 hours.

Cause of a Month

Roughly the time it takes for the Moon to complete one full orbit around the Earth, about 29.5 days.

Cause of a Year

One complete revolution of the Earth around the Sun, taking 365.25 days.

Cause of Day and Night

The rotation of the Earth on its axis; the side facing the Sun has day, while the side facing away has night.

Cause of Seasons

The 23.5-degree tilt of the Earth's axis as it revolves around the Sun, changing the intensity and directness of sunlight.

The Four Spheres of Earth

Biosphere (living things), Geosphere (solid earth), Hydrosphere (water), and Atmosphere (gases).

Biosphere

All living organisms on Earth and the environments they inhabit.

Geosphere

The solid part of the Earth, including rocks, minerals, landforms, and the interior.

Hydrosphere

All the water on Earth, including oceans, rivers, lakes, groundwater, and moisture in the air.

Atmosphere

The envelope of gases surrounding the Earth, held in place by gravity.

Greenhouse Gases

Gases in the atmosphere, such as carbon dioxide and water vapor, that trap heat and keep the planet warm.

Ozone Layer

A layer in the stratosphere that absorbs harmful ultraviolet (UV) radiation from the Sun.

Water Cycle

The continuous movement of water through evaporation, condensation, precipitation, and collection.

Structure of the Earth

Divided into four main layers: the crust, mantle, outer core, and inner core.

Tectonic Plates

Massive slabs of the Earth's solid outer shell that fit together like a jigsaw puzzle.

Divergent Plate Boundary

A boundary where tectonic plates move apart from each other, forming new crust.

Convergent Plate Boundary

A boundary where tectonic plates collide, leading to subduction or mountain building.

Transform Plate Boundary

A boundary where tectonic plates slide horizontally past one another, causing earthquakes.

New Zealand Geology

NZ sits astride the active boundary between the Australian and Pacific tectonic plates.

Pacific Ring of Fire

A major area around the Pacific basin with frequent earthquakes and volcanic eruptions.

Earthquake Focus

The point underground where an earthquake rupture begins.

Earthquake Epicenter

The point on the Earth's surface directly above the earthquake focus.

Magma vs. Lava

Magma is molten rock beneath the Earth's surface; lava has reached the surface.

Igneous Rock

Rock formed through the cooling and solidification of magma or lava.

Sedimentary Rock

Rock formed from the accumulation, compaction, and cementation of mineral particles.

Metamorphic Rock

Rock formed when existing rocks are transformed by intense heat and pressure.

Fossils

The preserved remains or traces of ancient organisms, typically found in sedimentary rocks.