NB G4 Scientific Literacy cheat sheet

Living organisms share life processes: they obtain and use energy, respond to stimuli, grow, reproduce, and are made of cells; nonliving things do not perform all of these.

The cell is the basic unit of life; unicellular organisms consist of one cell, while multicellular organisms have specialized cells, tissues, and organs.

Producers make food by photosynthesis using sunlight, water, and carbon dioxide; consumers obtain energy by eating other organisms; decomposers break down dead material and recycle nutrients.

In a food chain, arrows point from the organism being eaten to the eater, showing the direction of energy flow; a food web links multiple food chains.

An adaptation is an inherited trait that improves survival in a habitat; examples include camouflage, sharp claws, and the ability to store water.

Inherited traits come from parents through genetic material; environmental factors such as food and temperature can affect how traits develop.

A life cycle describes stages from germination or birth through growth, reproduction, and death; metamorphosis is a major change in body form during a life cycle.

An ecosystem includes living communities and nonliving factors such as sunlight, water, soil, and air; energy usually enters as sunlight, while matter cycles within the system.

Matter is anything with mass and volume; it is made of particles that are closely packed and vibrate in solids, loosely packed and flow in liquids, and far apart and move freely in gases.

Physical changes alter size, shape, or state without forming a new substance, while chemical changes produce new substances with different properties.

Evidence of a chemical change can include a new color, gas production, a new odor, heat release, or light emission; these signs alone do not always prove a chemical change.

Speed = distance ÷ time; average speed uses total distance divided by total time, and velocity includes both speed and direction.

A force is a push or pull; balanced forces do not change motion, while an unbalanced force changes an object's speed and/or direction.

Friction acts opposite the direction of motion between touching surfaces and converts motion energy into heat; rougher surfaces generally increase friction.

Gravity is a force that pulls objects with mass toward each other; on Earth it pulls objects toward Earth's center.

Energy can be transferred between objects or transformed from one form to another, such as electrical energy to light and heat in a lamp; energy is conserved in a closed system.

A simple circuit needs an energy source, a closed conducting path, and a device; conductors let electric charge flow easily, while insulators resist charge flow.

Earth has layers: a thin rocky crust, a hot mantle, a liquid outer core, and a solid inner core; temperature and pressure increase toward the center.

Igneous rock forms when magma or lava cools; sedimentary rock forms from compacted and cemented sediments; metamorphic rock forms when existing rock is changed by heat and pressure.

Weathering breaks rock into smaller pieces; erosion moves the pieces; deposition places them in a new location.

The water cycle includes evaporation, condensation, precipitation, runoff, and collection; the Sun provides most of the energy that drives it.

Weather is the short-term state of the atmosphere, while climate is the average pattern of weather in a region over many years.

Earth rotates on its axis about once every 24 hours, causing day and night; Earth revolves around the Sun about once every 365.25 days.

Earth's tilted axis and its revolution around the Sun cause seasons; the hemisphere tilted toward the Sun receives more direct sunlight and has summer.

Moon phases occur because the amount of the Moon's sunlit side visible from Earth changes as the Moon orbits Earth; the Moon does not make its own light.

The solar system has eight planets orbiting the Sun; in order from the Sun they are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.

A scientific question can be investigated with evidence and measurements; a hypothesis is a testable predicted answer based on prior knowledge.

In a fair test, the independent variable is deliberately changed, the dependent variable is measured, and controlled variables are kept the same.

Changing more than one variable at a time can make it unclear which factor caused the observed result.

Repeated trials and multiple observations improve reliability by reducing the effect of random errors.

Qualitative observations use words or categories, such as color or texture; quantitative observations use numbers and units, such as 12 cm or 25 °C.

A data table organizes measurements; a bar graph compares categories, a line graph shows change over time, and a pictograph uses symbols to represent counts.

A conclusion is supported by data and states whether the hypothesis was supported or not supported; opinion alone is not evidence.

Models represent real systems but are simplified and have limitations; models are revised when new evidence shows they do not match observations.

Measure with a tool and unit suited to the property, such as a ruler for length, a balance for mass, a thermometer for temperature, and a graduated cylinder for liquid volume.

Science aims to explain the natural world, while engineering aims to solve practical problems by designing and testing solutions.

The engineering design process includes defining a problem, gathering information, planning a solution, building a prototype, testing it, and improving it.

Renewable resources, such as sunlight, wind, and flowing water, are replenished naturally; nonrenewable resources, such as coal, oil, and natural gas, form very slowly and can be used up.

Human activities can add pollution to air, water, and land; pollution can harm organisms, ecosystems, and human health.

Technology can have intended benefits and unintended consequences, so decisions often involve trade-offs among cost, safety, effectiveness, and environmental impact.

Conservation means using resources carefully; reducing consumption, reusing items, and recycling materials can decrease waste and resource use.

Energy sources differ in availability, cost, and environmental effects; using energy more efficiently can reduce the total amount needed.

Scientific tools and new technologies can extend observations and enable new investigations, such as telescopes, microscopes, and sensors.