salinity
salt
saprophyte
satellite
saturated
hydrocarbon
saturated solution
scales
science
scientific method
screw
scrubber
sea breeze
seafloor spreading
season
second law of
thermodynamics
secondary wave
sedimentary rock
a measure of the amount of salts
dissolved in seawater.
compound formed when negative ions from
an acid combine with positive ions from a
base.
organism that uses dead organisms as a
food source and helps recycle nutrients
so they are available for use by other
organisms.
any natural or artificial object that
revolves around another object.
compound, such as propane or methane,
that contains only single bonds between
carbon atoms.
any solution that contains all the solute
it can hold at a given temperature.
thin, hard plates that cover a fish’s
skin and protect its body.
process of looking at and studying things
in the world in order to gain knowledge.
organized set of investigation procedures
that can include stating a problem,
forming a hypothesis, researching and
gathering information, testing a
hypothesis, analyzing data, and drawing
conclusions.
simple machine that consists of an
inclined plane wrapped in a spiral around
a cylindrical post.
device that lowers sulfur emissions from
coal-burning power plants.
movement of air from sea to land during
the day when cooler air from above the
water moves over the land, forcing the
heated, less dense air above the land to
rise.
Hess’s theory that new seafloor is formed
when magma is forced upward toward the
surface at a mid-ocean ridge.
short period of climate change in an area
caused by the tilt of Earth’s axis as
Earth revolves around the Sun.
states that is impossible for heat to
flow from a cool object to a warmer
object unless work is done.
seismic wave that moves rock particles at
right angles to the direction of the
wave.
a type of rock, such as limestone, that
is most likely to contain fossils and is
sediments
seismic wave
seismograph
semen
semiconductor
series circuit
sessile
setae
sewage
sex-linked gene
sexual reproduction
sexually
transmitted disease
(STD)
sheet erosion
shield volcano
short-day plant
formed when layers of sand, silt, clay,
or mud are cemented and compacted
together or when minerals are deposited
from a solution.
loose materials, such as rock fragments,
mineral grains, and the remains of onceliving plants and animals, that have been
moved by wind, water, ice, or gravity.
wave generated by an earthquake.
instrument used to register earthquake
waves and record the time that each
arrived.
mixture of sperm and a fluid that helps
sperm move and supplies them with an
energy source.
materials having conductivity properties
between that of metals (good conductors)
and nonmetals (insulators) and having
controllable conductivity parameters.
circuit in which electric current has
only one path to follow.
describes an organism that remains
attached to one place during most of its
lifetime.
bristlelike structures on the outside of
each body segment that helps segmented
worms move.
water that goes into drains and contains
human waste, household detergents, and
soaps.
an allele inherited on a sex chromosome
and that can cause human genetic
disorders such as color blindness and
hemophilia.
a type of reproduction in which two sex
cells, usually an egg and a sperm, join
to form a zygote, which will develop into
a new organism with a unique identity.
infectious disease, such as chlamydia,
AIDS, or genital herpes, that is passed
from one person to another during sexual
contact.
a type of surface water erosion caused by
runoff that occurs when water flowing as
sheets picks up sediments and carries
them away.
broad, gently sloping volcano formed by
quiet eruptions of basaltic lava.
plant that generally requires long
nights—12 or more hours of darkness—to
SI
silicate
sill
simple machine
single-displacement
reaction
skeletal muscle
skeletal system
sliding friction
slump
smooth muscle
soaps
social behavior
society
soil profile
soil
begin the flowering process.
International System of Units—the
improved, universally accepted version of
the metric system that is based on
multiples of ten and includes the meter
(m), liter (L), and kilogram (kg).
describes a mineral that contains silicon
and oxygen and usually one or more other
elements.
igneous rock feature formed when magma is
squeezed into a horizontal crack between
layers of rock and hardens underground.
machine that does work with only one
movement—lever, pulley, wheel and axle,
inclined plane, screw, and wedge.
chemical reaction in which one element
replaces another element in a compound.
voluntary, striated muscle that moves
bones, works in pairs, and is attached to
bones by tendons.
all the bones in the body; forms an
internal, living framework that provides
shape and support, protects internal
organs, moves bones, forms blood cells,
and stores calcium and phosphorus
compounds for later use.
frictional force that opposes the motion
of two surfaces sliding past each other.
a type of mass movement that occurs when
a mass of material moves down a curved
slope.
involuntary, nonstriated muscle that
controls movement of internal organs.
organic salts with nonpolar, hydrocarbon
ends that interact with oils and dirt and
polar ends that helps them dissolve in
water.
interactions among members of the same
species, including courtship and mating,
getting food, caring for young, and
protecting each other.
a group of animals of the same species
that live and work together in an
organized way, with each member doing a
specific job.
vertical section of soil layers, each of
which is a horizon.
mixture of mineral and rock particles,
the remains of dead organisms, air, and
water that forms the topmost layer of
solar collector
solar eclipse
solar energy
solar system
solenoid
solstice
solubility
solute
solution
solvent
sonar
sori
sound quality
space probe
space shuttle
space station
species
specific gravity
specific heat
Earth’s crust and supports plant growth.
device used in an active solar heating
system that absorbs radiant energy from
the Sun.
occurs when the Moon passes directly
between the Sun and Earth and casts a
shadow over part of Earth.
energy from the Sun that is clean,
inexhaustible, and can be transformed
into electricity by solar cells.
system of nine planets, including Earth,
and other objects that revolve around the
Sun.
a wire wrapped into a cylindrical coil.
twice-yearly point at which the Sun
reaches its greatest distance north or
south of the equator.
maximum amount of a solute that can be
dissolved in a given amount of solvent at
a given temperature.
in a solution, the substance being
dissolved.
a mixture which is evenly mixed
throughout; also known as a homogeneous
mixture.
in a solution, the substance in which the
solute is dissolved.
system that uses the reflection of sound
waves to detect objects underwater.
fern structures in which spores are
produced.
difference between sounds having the same
pitch and loudness.
instrument that travels far into the
solar system and gathers data that it
sends them back to Earth.
reusable spacecraft that can carry cargo,
astronauts, and satellites to and from
space.
large facility with living quarters, work
and exercise areas, and equipment and
support systems for humans to live and
work in space and conduct research.
group of organisms that reproduces only
with other members of their own group.
ratio of a mineral’s weight compared with
the weight of an equal volume of water.
amount of thermal energy needed to raise
the temperature of 1 kg of a material
1°C.
speed
sperm
sphere
spiracles
spontaneous
generation
sporangium
spores
sporophyte stage
spring
stamen
standard
standing wave
static electricity
static friction
station model
stinging cells
stomata
distance an object travels per unit of
time.
haploid sex cell formed in the male
reproductive organs; in humans, male
reproductive cells produced in the
testes.
a round, three-dimensional object whose
surface is the same distance from its
center at all points; Earth is a sphere
that bulges somewhat at the equator and
is slightly flattened at the poles.
openings in the abdomen and thorax of
insects through which air enters and
waste gases leave.
idea that living things come from
nonliving things.
round spore case of a zygote fungus.
waterproof reproductive cell of a fungus
that can grow into a new organism; in
plants, haploid cells produced in the
gametophyte stage that can divide by
mitosis to form plant structures or an
entire new plant or can develop into sex
cells.
plant life-cycle stage that begins when
an egg is fertilized by a sperm.
forms when the water table meets Earth’s
surface; often found on hillsides and
used as a freshwater source.
male reproductive organ inside the flower
of an angiosperm; consists of an anther,
where pollen grains form, and a filament.
exact, agreed-upon quantity used for
comparison.
a wave pattern that forms when waves of
equal wavelength and amplitude, but
traveling in opposite directions,
continuously interfere with each other;
has points called nodes that do not move.
the accumulation of excess electric
charge on an object.
frictional force that prevents two
surfaces from sliding past each other.
indicates weather conditions at a
specific location, using a combination of
symbols on a map.
capsules with coiled triggerlike
structures that help cnidarians capture
food.
tiny openings in a plant’s epidermis
streak
stream discharge
strike-slip fault
strong force
sublimation
substance
substituted
hydrocarbon
succession
sunspots
supergiant
supersaturated
solution
surface current
surface wave
suspension
symbiosis
synapse
through which carbon dioxide, water
vapor, and oxygen enter and exit.
color of a mineral when it is in powdered
form.
volume of water that flows past a
specific point per unit of time.
break in rock caused by shear forces,
where rocks move past each other without
much vertical movement.
attractive force that acts between
protons and neutrons in an atomic
nucleus.
the process of a solid changing directly
to a vapor without forming a liquid.
element or compound that cannot be broken
down into simpler components and maintain
the properties of the original substance.
hydrocarbon with one or more of its
hydrogen atoms replaced by atoms or
groups of other elements.
natural, gradual changes in the types of
species that live in an area; can be
primary or secondary.
areas on the Sun’s surface that are
cooler and less bright than surrounding
areas, are caused by the Sun’s magnetic
field, and occur in cycles.
late stage in the life cycle of a massive
star in which the core heats up, heavy
elements form by fusion, and the star
expands; can eventually explode to form a
supernova.
any solution that contains more solute
than a saturated solution at the same
temperature.
wind-powered ocean current that moves
water horizontally, parallel to Earth’s
surface, and moves only the upper few
hundred meters of seawater.
seismic wave that moves rock particles
up-and-down in a backward rolling motion
and side-to-side in a swaying motion.
heterogeneous mixture containing a liquid
in which visible particles settle.
any close relationship between species,
including mutualism, commensalism, and
parasitism.
small space across which an impulse moves
from an axon to the dendrites or cell
body of another neuron.
synthesis reaction
synthetic
systemic
circulation
chemical reaction in which two or more
substances combine to form a different
substance.
describes polymers, such as plastics,
adhesives, and surface coatings, that are
made from hydrocarbons.
largest part of the circulatory system,
in which oxygen-rich blood flows to all
the organs and body tissues, except the
heart and lungs, and oxygen-poor blood is
returned to the heart.