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97 terms

science vocab

organism that relies on other organisms for its energy and food supply; also called a heterotroph
organism that obtains energy by eating only plants
organism that obtains energy by eating animals
organism that obtains energy by eating both plants and animals
organism that feeds on plant and animal remains and other dead matter
organism that breaks down and obtains energy from dead organic matter
food chain
series of steps in an ecosystem in which organisms transfer energy by eating and being eaten
food web
network of complex interactions formed by the feeding relationships among the various organisms in an ecosystem
trophic level
step in a food chain or food web
ecological pyramid
diagram that shows the relative amounts of energy or matter within each trophic level in a food chain or food web
total amount of living tissue within a given trophic level
scientific study of interactions among organisms and between organisms and their environment
all life on earth; the parts of the solid earth, hydrosphere, and atmosphere in which lviving organisms can be found
group of similar organisms that can breed and produce fertile offspring
group of individuals of the same species that live in the same area
assemblage of different populations that live together in a defined area
collection of all the organisms that live in a particular place, together with their nonliving environment
group of ecosystems that have the same climate and dominant communities
organism that can capture energy from sunlight or chemicals and use it to produce its own food from inorganic compounds; also called a producer
organism that can capture energy from sunlight or chemicals and use it to produce food from inorganic compounds; also called an autotroph
the process by which plants, algae, and certain prokaryotes use light energy to convert water and carbon dioxide into energy-rich glucose molecules
the process by which certain microorganisms use chemical energy to produce food
organism that obtains energy from the foods it consumes; also called a consumer
ability to move
what is not a characteristic of all living things?
the amount of light and temperature
factors to which living things respond
an atmosphere containing oxygen gas
what was not a characteristic of earth before the oceans formed
hydrogen cyanide and carbon monoxide
two gases that probably existed in earth's early atmosphere are
the presence of liquid water
one necessary condition for the evolution of the first life on earth was
some became extinct, some survived in only a few airless habitats, some evolved metabolic pathways that used oxygen for respiration
what was the response of the various groups of early organisms that existed when oxygen levels rose in the atmosphere
representatives of most animal groups
the cambrian explosion resulted in the evolution of the first
by making new habitats available to them
in the past, mass extinctions encouraged the rapid evolution of surviving species
simulate lightning
in miller-urey's experiments with the origin of life forms, electric sparks were passed through a mixture of gases to
earth's first atmosphere contained little or no
it can be tested
what makes a hypothesis scientifically useful
scientists state a possible explanation for how and why things happen
quantitative observation
the statement "a worm is 2 cm long" is a
a logical interpretation of an observation
to be useful in science, a hypothesis must be
one meter is equal to
in this stage the outer layer of the star is ejected while the core collapses
white dwarf
the remains of a low and medium mass star
red giant
hydrogen fusion is still progressing in the star's outer shell, no fusion is taking place in the core
main sequence
90% of stars are spent in this stage, a fine balance between gravity and gas pressure
dark, cool clouds full of interstellar matter which are the birthplace of stars
black hole
these are very hot and massive. their gravity is so strong that light cannot even escape it
a large red object that is not yet hot enough to engage in nuclear fusion
neutron star
these stellar remnants of a supernova are extremely massive, dense, and spin rapidly. protons and electrons are combined
dense, hot, supermassive ball
according to the big bang theory, the entire universe began as a
within one of the spirals
according to information received from radio telescopes, where is our sun positioned in the milky way?
when a star is thought to be born
a protostar reaches a temperature high enough for nuclear fusion to begin
elliptical galaxies
about 60 percent of all known galaxies are classified as
hubble's law states that galaxies are retreating form earth at a speed that is proportional to their
9.5 trillion km
approximately how long is a light year?
cosmic microwave background radiation
what is supportive evidence of the big bang theory?
main sequence
which type of star is the sun
red shift of distant galaxies
scientists know the universe is expanding because of the
white dwarf
what remains after a low-mass or medium-mass star dies?
10,000 light years thick
at its nucleus, the milky way galaxy is about 100,000 light years wide and about
run out of fuel and collapse
all stars, regardless of their size, eventually
characteristics of living things
1. made up of units called cells 2. reproduce 3. are based on a universal genetic code 3. grow and develop 5. obtain and use materials and energy 6. respond to their environment 7. taken as a group, change over time.
process by which organisms maintain a relatively stable internal environment
a tentative explanation that is tested to determine if it is valid
a well-tested and widely accepted view that explains certain observable facts
only 10% of energy is transferred to the next level, the other 90% is "lost" as heat
what is the 10% rule? what happens to the other 90%?
energy is "lost", whereas nutrients can be recycled
compare the movement of energy and nutrients through living systems
ecological model
diagram that shows the relative amounts of energy or matter within each trophic level in a food chain or food web. a pyramid promotes the most stability
what percentage of all species that ever lived on earth has become extinct?
there was a lot of magma and volcanic activity. hydrogen cyanide, carbon dioxide, carbon monoxide, nitrogen, hydrogen sulfide and water were the substances that probably made up early earth's atmosphere
what was the early earth like? atmosphere (gasses)? activity?
what was one necessary condition for the evolution of life?
a rapid diversification of marine life over a short amount of time. after a mass extinction, a different organism/species prospers (explodes)
what was the cambrian explosion? how does a rapid diversification of life relate to a mass extinction?
terrestrial (small and rocky): mercury, venus, earth, mars. jovian (huge gas giants): jupiter, saturn, uranus, neptune
list the terrestrial planets. list the gasseous or jovian planets
white light into the color spectrum
what does a prism do?
according to the nebular theory, it formed from a rotating cloud of dust and gas
how did the solar system form?
tells whether a star is going toward or away from us
what does the use of the doppler effect tell astronomers about a star?
difference between absorption spectrum and emission spectrum. what can a star's spectrum tell astronomers about that star?
absorption: a continuous spectrum produced when white light is passed through a cool gas under low press; the gas absorbs selected wavelengths of light, and the spectrum looks like it has dark lines superimposed. emission: a series of bright lines of particular wavelengths produced by a hot gas under low pressure. tells us what it's made of what's surrounding
the distance light travels in one year; about 9.5 trillion km.
how long is a light year? what is a light year?
spiral galaxy. 100,000 l.y. wide, 10,000 l.y. thick
what is the size and structure of the milky way galaxy?
what is the most common type of galaxy in the universe?
big bang theory
theory that proposes that the universe originate as a single mass, which subsequently exploded
evidence for big bang
cosmic microwave background radiation and the expanding universe
doppler effect
change in the apparent frequency of a wave as observer and source move toward or away from each other
red shift
a shift in the spectra of distant galaxies toward longer wavelengths; generally interpreted as the Doppler effect resulting from the velocity at which they recede as the universe expands
matter or the quantity of matter evaporated or passed off in vapor
the result of being made more compact or dense
rain, snow, sleet, or hail that falls to the ground
large ice sheet
pieces that break off glaciers into ocean, float away as icebergs, and melt
piece of glacier that break off into ocean
the slow passage of a liquid through a filtering medium
dismiss, unload, release
plants absorb groundwater through their roots and release it through the pores of their leaves as water vapor into the atmosphere
plants are removing co2 from the atmosphere while animals are adding it
locked up in the crust in limestone rocks
where is the largest amount of carbon
in fossil fuels, atmosphere as co2, in living and dead biological tissue, dissolved in seawater
where else is carbon
low mass
nebula-protostar-main sequence-white dwarf-black dwarf
medium mass
nebula-protostar-main sequence-red giant-planetary nebula-white dwarf-black dwarf
nebula-protostar-main sequence-red super giant-supernova explosion-neutron star OR black dwarf