Science Exam Review: Physics, Chemistry, and Biology

Comprehensive vocabulary flashcards covering Newton's Laws, simple machines, particle and atomic theories, cell biology, DNA, and microbiology.

Newton's First Law (Law of Inertia)

A principle stating that an object at rest stays at rest, and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced, external force.

Inertia

An object's resistance to changing its state of motion.

Newton's Second Law (Law of Acceleration)

The principle stating the acceleration of an object is directly proportional to the net force acting upon it and inversely proportional to its mass, expressed by the formula $F = MA$.

Newton's Third Law (Law of Action-Reaction)

A law stating that for every action force, there is an equal and opposite reaction force.

Lever

A simple machine consisting of a rigid bar resting on a pivot (fulcrum) used to move heavy loads with less effort.

Wheel and Axle

A simple machine featuring a circular wheel fastened to a central axle, designed to reduce friction and multiply force for lifting or moving objects.

Inclined Plane

A flat, sloped surface that allows heavy loads to be raised or lowered with less force than lifting directly.

Wedge

A triangular-shaped tool used to split, cut, or fasten materials by pushing them apart.

Pulley

A wheel with a groove for a rope, used to lift or move loads, often in combination to reduce required energy.

Screw

An inclined plane wrapped around a cylinder, used to fasten materials or lift objects through rotational force.

Particle Theory of Matter

A scientific theory stating that all physical matter consists of tiny, constantly moving particles (atoms or molecules) that have spaces between them and are attracted to each other.

Solids

A state of matter where particles are packed tightly in a rigid structure, vibrating in place.

Liquids

A state of matter where particles are close together but can move past each other, allowing them to flow.

Gases

A state of matter where particles are far apart, moving rapidly and randomly.

Atomic Theory

The scientific framework stating that all matter is composed of discrete units called atoms, which are rearranged during chemical reactions but not created or destroyed.

Protons

Subatomic particles with a charge of $+1$.

Neutrons

Subatomic particles with a charge of $0$.

Electrons

Subatomic particles with a charge of $-1$, which exist in cloud-like regions around the nucleus.

Atomic Number

The specific number of protons that defines the identity of an element.

Isotopes

Atoms of the same element that have different numbers of neutrons, resulting in different atomic masses.

Viscosity

A physical property representing a fluid's internal resistance to flow or deformation, often described as its "thickness."

Pascal’s Law

The principle stating that an increase in pressure applied to a confined, incompressible fluid at any point is transmitted equally and undiminished in all directions.

Cell Theory

A biological principle stating that all living organisms are composed of one or more cells, cells are the basic structural and functional units of life, and all cells arise from pre-existing cells.

Diffusion

The net movement of anything (atoms, ions, molecules, energy) from a region of higher concentration to a region of lower concentration.

Osmosis

The diffusion of water from a greater to a lesser water concentration across a selectively permeable membrane.

Autotrophs

Organisms, such as plants, that use chloroplasts to turn sunlight into energy.

Heterotrophs

Organisms, such as animals, that rely on mitochondria to break down nutrients for energy.

Cell Specialization (Differentiation)

The process where generic stem cells develop into specific cell types with unique structures and functions.

DNA

A long polymer made of nucleotides containing deoxyribose, a phosphate group, and a base, which stores genetic information and regulates cell activities.

Chromosomes

Compact structures into which DNA is packed.

Bacteria

Complex, single-celled prokaryotes with cell walls that reproduce independently through binary fission.

Viruses

Simple entities consisting of genetic material (DNA or RNA) encased in a protein coat that must hijack a host cell to reproduce.

Antibiotics

Medicines used to kill bacteria, which have no effect on viruses.