GACE Middle Grades Science (705) cheat sheet

Hypothesis: a testable, falsifiable prediction; a theory is a well-substantiated explanation supported by many lines of evidence, not a guess.

Independent variable is manipulated by the researcher; dependent variable is measured; controlled variables are held constant to prevent confounding.

A valid experiment includes a control group and, where possible, random assignment and blinding to reduce bias.

Accuracy is closeness to the true value; precision is repeatability of measurements; random error affects precision, systematic error affects accuracy.

Significant figures: multiplication/division results carry the fewest sig figs of the inputs; addition/subtraction results carry the fewest decimal places.

Scientific claims are evaluated by peer review, replication, and consistency with existing evidence; anecdotal evidence and authority alone are insufficient.

Correlation does not establish causation; a controlled experiment or strong mechanistic evidence is needed to infer cause and effect.

Scientific laws describe observed regularities (e.g., Newton's law of gravitation); theories explain them; one does not become the other.

Ethical conduct includes honest data reporting, proper citation, informed consent in human studies, and humane treatment of animal subjects.

Earth's layers: crust (thin, silicate), mantle (solid but slowly flowing silicate), outer core (liquid iron-nickel), inner core (solid iron-nickel).

Plate boundaries: divergent (new crust, mid-ocean ridges), convergent (subduction or collision, trenches, mountains), transform (lateral sliding, earthquakes).

Rock cycle: igneous forms from cooling magma/lava; sedimentary from compaction and cementation of sediments; metamorphic from heat and pressure without melting.

Weathering breaks rock in place; erosion transports sediment by water, wind, ice, or gravity; deposition lays it down.

Water cycle processes: evaporation, transpiration, condensation, precipitation, infiltration, runoff, and groundwater flow.

Earth's rotation (about 24 h) causes day/night and the apparent motion of stars; revolution (about 365.25 days) with a 23.5° axial tilt causes seasons.

Moon phases result from the changing angle between Earth, Moon, and Sun; a solar eclipse occurs at new moon, a lunar eclipse at full moon.

The solar system has eight planets; inner planets are small, dense, rocky, and outer planets are large, low-density gas/ice giants; the Sun holds most of the system's mass.

Stars form from collapsing nebulae, fuse hydrogen to helium on the main sequence, and later evolve to red giants and white dwarfs (low mass) or supernovae/neutron stars/black holes (high mass).

Cell theory: all living things are made of cells; the cell is the basic unit of life; all cells arise from pre-existing cells.

Prokaryotic cells lack a membrane-bound nucleus and organelles; eukaryotic cells have a nucleus, mitochondria, and (in plants) chloroplasts and a cell wall.

Photosynthesis: 6CO2 + 6H2O + light energy → C6H12O6 + 6O2, occurring in chloroplasts; cellular respiration reverses this to release ATP in mitochondria.

DNA structure: double helix of nucleotides with complementary base pairing (A–T, C–G); genes encode proteins via transcription and translation.

Mitosis produces two genetically identical diploid cells for growth and repair; meiosis produces four genetically varied haploid gametes.

Mendelian genetics: dominant alleles mask recessive ones; a Punnett square predicts offspring ratios from parental genotypes.

Natural selection requires heritable variation, differential reproductive success, and change in allele frequencies over generations.

Ecological levels: organism, population, community, ecosystem, biome, biosphere; energy flows through food webs and is lost as heat at each trophic level.

Homeostasis maintains stable internal conditions through feedback loops; negative feedback reverses a change, positive feedback amplifies it.

Newton's laws: inertia (no net force → constant velocity), F = ma, and equal-and-opposite action–reaction forces on different objects.

Speed = distance/time; velocity includes direction; acceleration = change in velocity/time; a net force causes acceleration, not necessarily motion.

Work = force × distance (in the force direction); power = work/time; kinetic energy = ½mv²; gravitational potential energy = mgh.

Conservation of energy: energy changes form but is neither created nor destroyed; friction converts mechanical energy to thermal energy.

Density = mass/volume; an object floats in a fluid if its density is less than the fluid's; pressure increases with depth in a fluid.

Ohm's law: V = IR; series circuits share current and add resistance; parallel circuits share voltage and add current paths.

Waves: speed = frequency × wavelength; transverse waves oscillate perpendicular to travel, longitudinal waves parallel; sound needs a medium, light does not.

Atomic structure: protons (+) and neutrons (neutral) in the nucleus; electrons (−) in energy levels; atomic number = protons, mass number = protons + neutrons.

Chemical reactions conserve mass and atoms; reactants rearrange into products; acids donate H⁺, bases accept H⁺, and pH measures hydrogen ion concentration.

Inquiry-based instruction engages students in questioning, investigation, data analysis, explanation, and argument from evidence.

The 5E model sequences a lesson as Engage, Explore, Explain, Elaborate, and Evaluate, with student exploration before formal explanation.

Formative assessment (exit tickets, questioning, observations) guides ongoing instruction; summative assessment measures achievement at the end of a unit.

Backward design starts with desired results and acceptable evidence, then plans learning experiences aligned to standards.

Misconceptions (e.g., seasons caused by distance from the Sun) should be elicited and confronted with evidence, not merely corrected verbally.

Safety: conduct only approved labs, use goggles and proper ventilation, know chemical disposal rules, and never allow unsupervised hazardous materials.

Differentiation adapts content, process, or product (e.g., leveled texts, flexible grouping, choice boards) while keeping the same learning goal.

Rubrics with clear criteria and performance levels make scoring of investigations and lab reports more reliable and transparent.

English learners and students with disabilities benefit from multimodal representations, sentence frames, and explicit vocabulary instruction in science.