MTTC Integrated Science (Secondary) (094) flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Independent variable

The variable the experimenter deliberately manipulates or changes in an experiment; its effect on the dependent variable is measured while other factors are controlled.

Control group

The group in an experiment that receives no treatment or a placebo, providing a baseline for comparison against the experimental group.

Accuracy versus precision

Accuracy is how close a measurement is to the true value; precision is how close repeated measurements are to each other. A measurement can be precise without being accurate.

Significant figures rules

Nonzero digits and captive zeros count; leading zeros do not; trailing zeros count only with a decimal point. Multiplication uses least sig figs; addition uses least decimal places.

Falsifiability

A property of scientific hypotheses meaning they can be tested and potentially proven wrong by observation or experiment; untestable claims fall outside empirical science.

Scientific theory

A well-substantiated explanatory framework supported by extensive evidence and repeatedly tested; it is not a guess and can be revised as new evidence emerges.

Mole and molar mass

One mole equals 6.022 × 10²³ particles; molar mass in grams per mole converts between mass and moles and is used in stoichiometric calculations.

Limiting reactant

The reactant consumed first in a chemical reaction; it determines the maximum amount of product formed (theoretical yield) based on the balanced equation's mole ratios.

Periodic trend: atomic radius

Atomic radius generally decreases across a period (increased nuclear charge pulls electrons closer) and increases down a group (added electron shells).

Ionic versus covalent bonding

Ionic bonds involve electron transfer between metals and nonmetals, forming charged ions; covalent bonds involve electron sharing between nonmetals.

Newton's second law

The net force on an object equals its mass times its acceleration (F = ma); acceleration is directly proportional to net force and inversely proportional to mass.

Conservation of energy

Energy cannot be created or destroyed, only transformed between forms such as kinetic, potential, thermal, and chemical, while total energy in a closed system remains constant.

Ohm's law

Current through a conductor equals voltage divided by resistance (I = V/R); electrical power is P = IV, relating current, voltage, and energy use.

Wave equation

Wave speed equals frequency times wavelength (v = fλ); frequency is set by the source, while speed depends on the medium through which the wave travels.

Cell theory

All living organisms are composed of one or more cells, the cell is the basic unit of life, and all cells arise from preexisting cells.

Prokaryote versus eukaryote

Prokaryotes lack a membrane-bound nucleus and organelles; eukaryotes have a nucleus and membrane-bound organelles such as mitochondria and chloroplasts.

Photosynthesis equation

Carbon dioxide and water, using light energy, produce glucose and oxygen (6CO₂ + 6H₂O + light → C₆H₁₂O₆ + 6O₂); the reverse process is cellular respiration.

DNA base pairing

In double-stranded DNA, adenine pairs with thymine and guanine pairs with cytosine; strands are antiparallel and replication is semiconservative.

Monohybrid cross ratio

A cross of two heterozygotes for one trait yields a 3:1 phenotypic ratio and a 1:2:1 genotypic ratio in offspring.

Natural selection conditions

Evolution by natural selection requires heritable variation, differential reproductive success, and environmental pressure acting over generations.

Trophic energy transfer

Energy flows one way through trophic levels, with roughly 10 percent transferred to the next level; the rest is lost mainly as heat.

Plate boundary types

Divergent boundaries create new crust, convergent boundaries produce subduction and mountains, and transform boundaries cause earthquakes as plates slide past each other.

Rock cycle

Igneous rock forms from cooling magma, sedimentary from compaction and cementation of sediments, and metamorphic from heat and pressure on existing rock.

Cause of seasons

Earth's axial tilt (about 23.5 degrees) changes the angle and duration of sunlight across the year, not the planet's distance from the Sun.

Kepler's laws

Planets orbit in ellipses, sweep equal areas in equal times, and the square of orbital period is proportional to the cube of semi-major axis.

Radiometric dating

Absolute dating uses the decay of radioactive isotopes at known half-lives to determine the age of rocks and fossils, establishing Earth's age near 4.6 billion years.

Relative dating principles

Superposition (older layers below), cross-cutting relationships, and index fossils establish the sequence of geologic events without assigning numerical ages.

Crosscutting concepts

Themes spanning all science domains: patterns; cause and effect; scale and proportion; systems and models; energy and matter; structure and function; stability and change.

Engineering design cycle

An iterative process of defining a problem, researching, prototyping, testing, and refining a solution while balancing criteria against constraints such as cost and safety.

Correlation versus causation

Two variables may change together without one causing the other; confounding variables or coincidence can produce a correlation, so controlled evidence is needed.

Random versus systematic error

Random error scatters measurements around a value and is reduced by averaging; systematic error shifts all measurements in one direction and requires calibration or correction.

Laboratory safety equipment

Eyewash stations, safety showers, fire extinguishers, and Safety Data Sheets must be located and understood before beginning any laboratory activity.