Science quiz vocab

Plant cells

have a square shape due to its rigid cell wall surrounding the membrane; also contain chloroplast for photosynthesis and a mitochondria for cellular respiration.

Nucleus

contains genetic material (DNA) that stores instructions for structures and function; Plants and animal cells are eukaryotic because they contain a nucleus.

Prokaryote

a unicellular (one called) organism that does not have a nucleus but does have floating DNA; ex- bacteria.

Biodiversity

variety of different species in an environment. The more biodiversity the greater the sustainability.

Biotic

living parts of the environment, such as Producers (autotrophs), consumers (heterotrophs), and decomposers.

Succession

primary succession starts with lichen and moss growing on rocks; secondary succession is the repopulation of an area starting with grasses and weeds in soil left behind after a disturbance.

Continental Drift Theory

a single landmass (Pangea) broke into pieces and drifted apart; later modified to become Plate Tectonics.

Convergent Boundary

area where tectonic plates move towards each other and collide, forming mountains, volcanic islands, and trenches.

Divergent Boundary

area where tectonic plates move away from each other or divide, forming rifts and ridges.

Transform Boundary

area where tectonic plates slide past each other, forming earthquakes along fault lines.

Atmospheric Pressure

high pressure is dry weather with clear skies; low pressure is overcast or rainy due to less dense air rising and condensing.

Cold Front

brings thunderstorms and leaves overcast and colder weather behind; symbolized by a blue line with icicle triangles.

Hurricane

mature tropical cyclone that forms in areas of low pressure over warm tropical oceans.

Convection

the circular motion of liquids or gasses caused by density differences (warm rises, cool sinks); drives currents in the ocean and mantle.

Hertzsprung-Russell Diagram

a graph that shows the relationship between a star's luminosity (brightness) and surface temperature (color).

Main-sequence

the diagonal region on the H-R diagram where stars spend most of their lives fusing hydrogen; the sun is currently a yellow main sequence star.

Nebula

a large cloud of dust and gas where stars are born.

Galaxy

systems of dust, gas, stars and interstellar matter; our solar system is 3/4 out on an arm in the spiral Milky Way Galaxy.

Rotation

an object spinning on its own axis; causes day and night.

Seasons

determined by both Earth's tilted axis relative to the sun and its position in revolution (orbit) around the sun.

Neap Tide

a tide just after the quarter moons when there is the least difference between high and low water.

Spring Tide

a tide just after a new or full moon when there is the greatest difference between high and low water.

Law of Inertia

Newton's First Law; an object's motion will not change unless an unbalanced force acts on it.

Unbalanced Forces

cause changes in motion of an object; net force is greater than zero.

Law of Force and Acceleration

Newton's Second Law; acceleration depends on mass and amount of force applied (F=ma).

Balanced Forces

forces acting on an object that cancel each other out, causing no change in movement.

Law of Action-Reaction

Newton's Third Law; all forces occur in contact pairs where every action force has a reaction force equal in strength and opposite in direction.

Velocity

speed in a given direction.

Kinetic Energy

energy of objects in motion; faster motion means greater kinetic energy.

Potential Energy

stored energy of an object due to position, condition, or composition; higher off the ground means greater potential energy.

Chemical Change

a reaction where a new substance is made; evidence includes creation of light, precipitate, gas, color change, or temperature change.

Law of Conservation of Mass

mass stays the same during a reaction; matter is not created or destroyed, just rearranged.

Chemical Formula

a set of chemical symbols and subscripts showing which elements are bonded together; coefficients identify the number of molecules.

Atom

the smallest particle of matter that has distinct properties; identified by the number of protons (atomic number).