GED Science Lecture Notes Review

Vocabulary flashcards covering fundamental experimental, biological, chemical, physical, and earth science concepts from the GED Science review lecture.

Independent variable

The variable in an experiment that the scientist changes on purpose.

Dependent variable

The variable in an experiment that the scientist measures or observes.

Controlled variables

Conditions kept the same throughout an experiment to ensure it is fair.

Hypothesis

A testable prediction about the outcome of an experiment.

Positive relationship

A pattern in data where as $X$ increases, $Y$ also increases.

Negative relationship

A pattern in data where as $X$ increases, $Y$ decreases.

Cell

The basic structural and functional unit of life.

Nucleus

The control center of the cell that contains DNA.

Cell membrane

The cellular structure that controls what enters and leaves the cell.

Mitochondria

Cellular organelles that produce usable energy for the cell.

Ribosomes

Cellular structures responsible for making proteins.

Chloroplasts

Organelles found in plant cells that are used for photosynthesis.

Photosynthesis

The process by which plants use sunlight, water, and carbon dioxide to produce glucose and oxygen.

Cellular respiration

The metabolic process that breaks down glucose and oxygen to release usable energy, carbon dioxide, and water.

Gene

A section of DNA that influences a specific trait.

Chromosome

A cellular structure composed of DNA.

Dominant allele

An allele that expresses its trait when only one copy is present.

Recessive trait

A genetic trait that generally requires two recessive copies of an allele to be expressed.

Mutation

A change in DNA that can be harmful, helpful, or neutral.

Natural selection

The process where organisms with traits that help them survive and reproduce are more likely to pass those traits to future generations.

Virus

A biological entity that requires a host cell to reproduce.

Bacteria

Living single-celled organisms, some of which cause disease.

Vaccine

A substance that helps the immune system recognize a pathogen and prepare an immune response.

Protons

Positively charged ($+$) subatomic particles located inside the nucleus of an atom.

Neutrons

Subatomic particles with no charge (neutral) located inside the nucleus of an atom.

Electrons

Negatively charged ($-$) subatomic particles located around the nucleus of an atom.

Element

A pure substance made of only one type of atom.

Compound

A substance composed of two or more different elements chemically joined together.

Mixture

A combination of two or more substances that are physically combined.

Physical change

A change in which the substance itself does not transform into a new substance.

Chemical change

A change in which a new substance is formed.

Kinetic energy

The energy an object possesses due to its motion.

Potential energy

Energy that is stored within an object or system.

Speed

The rate at which an object covers distance, calculated as $\text{speed} = \text{distance} \div \text{time}$.

Acceleration

A change in velocity, which occurs when an object speeds up, slows down, or changes direction.

Force

A push or pull exerted on an object.

Gravity

A force that pulls objects toward each other, such as toward Earth's center.

Friction

A force that opposes motion between surfaces in contact.

Current

The flow of electric charge.

Voltage

Electrical potential difference, expressed in the formula $V = I \times R$.

Resistance

The opposition to the flow of electric current.

Evaporation

The process by which a substance changes state from liquid to gas.

Condensation

The process by which a substance changes state from gas to liquid.

Precipitation

Water released from clouds in the form of rain, snow, sleet, or hail.

Rotation

The spinning of Earth on its axis, which causes day and night.

Revolution

The movement of Earth around the Sun, taking approximately one year.

Renewable resources

Energy sources or materials that can naturally be replaced relatively quickly.

Nonrenewable resources

Energy sources or materials with limited supplies that take extremely long periods to form.