grade 6 revision q3 Flashcards
occurs when individuals join a population.
immigration
occurs when individuals leave a population.
emigration
is the maximum number of individuals of one species that the environment can support.
carrying capacity
occurs when the carrying capacity for a population
suddenly drops.
population crash
A part of the environment that keeps a population’s size at a level below its full potential
limiting factor
When two or more individuals or populations try to use the same limited resource.
competition
occurs when individuals work together.
cooperation
A close long-term relationship between two different populations in a community
symbiosis
A symbiotic relationship in which both organisms benefit
mutualism
A symbiotic relationship in which one organism benefits while the other is unaffected
commensalism
A symbiotic relationship in which one organism benefits and another is harmed
parasitism
is the ability to do work.
energy
is anything that has mass and takes up space.
matter
the original source of energy in most ecosystems.
sun
states that energy cannot be created or destroyed; it only changes from one form to another.
law of conservation of energy
states that mass cannot be created or destroyed.
law of conservation of mass
get energy by eating producers.
primary consumers
get energy by eating primary consumers,
secondary consumers
is a tool that can be used to trace the flow of energy
through an ecosystem.
energy pyramid
The movement of water between the oceans, atmosphere, land, and living things
water cycle
is caused by any material or condition that harms the
environment.
pollution
occurs when a large fraction of a resource has
been used up.
resource depletion
Human population growth in and around cities
urbanization
An increase in the amount of nutrients, such as nitrates, in an aquatic ecosystem
eutrophication
is the protection and wise use of natural resources.
conservation
the smallest particle into which an element can be divided and still be the same element.
atom
thought that matter could be divided into
smaller units until you obtain a particle that cannot be divided anymore.
Democritus
published an atomic theory, stating that all
matter is made up of atoms that cannot be created, divided, or destroyed.
John Dalton
provided evidence that atoms contain negatively charged particles, which were later called electrons.
J.J Thomson
suggested that atoms have a nucleus - a small, dense center that has a positive charge.
Ernest Rutherford
suggested a model in which electrons move around the nucleus in circular paths.
Niels Bohr
discovered that the nucleus contains uncharged
particles called neutrons.
James Chadwick
the positively charged particles of atoms.
protons
are particles that have no electrical charge.
Neutrons
The negatively charged particles of an atom
electrons
The number of protons in the nucleus of an atom
atomic number
The total number of protons and neutrons in an atom’s nucleus
mass number
atoms of the same element that have different
numbers of neutrons.
Isotopes
is any natural material that is used by humans.
Natural resource
is a natural resource that can be replaced at
the same rate at which it is consumed.
renewable resource
is a resource that forms at a rate much
slower than the rate at which it is consumed.
non-renewable resource
is a nonrenewable resource formed from the
buried remains of plants and animals that lived long ago.
fossil fuel
Natural resources that are used to make objects, food, or drink
material resources
removes electrons from hydrogen atoms, and electron
movement generates electrical energy.
the fuel cell
is an exact quantity that people agree to use to
compare measurements.
standard
the distance between two points.
length
The amount of space occupied by an object
volume
the quantity of matter in an object.
mass
mass per unit volume of a material.
Density
is a measure of how hot or how cold something is.
Temperature
the interval between two events.
Time
