LIFE SCIENCE ECOLOGY UNIT TEST
Vocabulary to Know
Biosphere
Part of the Earth that supports life, including the top portion of Earth’s crust, the
atmosphere, and all the water on the Earth’s surface
Biotic Potential A population’s highest rate of reproduction under ideal conditions
Carnivore
Type of consumer; An animal that eats other animals
Carrying
Largest number of individuals of a particular species that an ecosystem can support
capacity
over time
Chemosynthesis Process in which producers make energy-rich nutrient molecules from chemicals
Commensalism Type of symbiotic relationship in which one organism benefits and the other
organism is not affected
Community
All the populations of different species that live in an ecosystem
Consumer
Organism that cannot create energy-rich molecules but obtains its food by eating
other organisms
Cooperation
Interactions among individual organisms in ways that improve survival
Decomposer
Type of consumer; An animal that breaks down dead organisms and wastes into
simpler substances
Ecology
Study of interactions that take place among organisms and their environment
Ecosystem
All the living organisms that live in an area and the nonliving features of their
environment
Energy pyramid Model that shows the amount of energy available at each feeding level in an
ecosystem
Exponential
Type of population growth; The larger a population becomes, the faster it grows
Growth
Food web
Model that shows the complex feeding relationships among organisms in a
community
Habitat
Place where an organism lives and that provides the types of food, shelter, moisture,
and temperature needed for survival
Herbivore
Type of consumer; An animal that eats only plants or plant parts
Limiting factor
Anything that can restrict the size of a population, including living and nonliving
features of an ecosystem, such as predators or drought.
Mutualism
Type of symbiotic relationship in which both organisms benefit
Niche
In an ecosystem, refers to the unique ways an organism survives, obtains food and
shelter, and avoids danger
Omnivore
Type of consumer; An animal that eats both plants and other animals
Parasitism
Type of symbiotic relationship in which one organism benefits and the other
organism is harmed
Population
All the organisms that belong to the same species living in a community
Producer
Organism, such as a green plant or alga, that uses an outside source of energy like
the Sun to create energy-rich food molecules
Scavenger
Type of consumer; An animal that eats the remains of other organisms
Symbiosis
Any close relationship between species, including mutualism, commensalism, and
parasitism
Concepts to Know
Levels of ecological organization, Biosphere  Ecosystem  Community  Population  Habitat
from largest to smallest
Define
Competition occurs when two or more organisms seek the same resource at the
competition
same time
Food
One way organisms can limit each other’s population size. If
Name two things over
food is limited, population strength and size will be, too.
which organisms compete
Living
Another way organisms can limit each other’s population
space
size. If living space is limited, population size will be, too.
Describe the degree of competition
In nature, the most intense competition is usually among
between individuals of the same species individuals of the same species, because they need the same
kinds of food and shelter.
Draw graph
describing
different types
of population
growth
If a population begins to exceed the environment’s carrying capacity,
some individuals will not have enough resources. Those organisms could
die or be forced to move elsewhere.
A population can also experience steady growth, determined by the
carrying capacity. That population does not exceed what the environment
can provide for it.
Differentiate
Photosynthetic Producers use sunlight + chlorophyll to produce energy-rich
between two
molecules
types of
Chemosynthetic Producers use mineral molecules in water to produce energy-rich
producers
molecules
Differentiate between four types of consumers – SEE DEFINITIONS
Lichens = Alga living within tissues of fungus. Alga supplies energy
Mutualism
to itself & fungus thru photosynthesis. Fungus supplies protected
space for alga to live.
Clown fish can swim among sea anemone’s tentacles without
Know
Commensalism harm. Sea anemone’s tentacles protect the clown fish from
examples of…
predators.
Roundworm attaches itself to inside of pet’s intestine and feeds
Parasitism
on nutrients in the pet’s blood. Because the puppy can’t receive
the nutrients the worm steals, it becomes sick or could die.
Define predator
Predator
Consumer that captures and eats other consumers
& prey
Prey
Consumer that is captured and eaten by the predator
Explain graph – How does
carrying capacity influence
the number of organisms
in an ecosystem
Why is sunlight
the energy
source for
almost all life
on Earth?
Producers convert light energy (from the Sun) into chemical energy that is stored in
sugar molecules during photosynthesis. Because consumers can’t make their own
food, energy is only passed on to consumers when they eat producers or other
consumers that have eaten producers. Photosynthesis cannot occur is no light is
available. Therefore, all energy exchanged begins with energy from the Sun being
converted and transferred.
Matter can be recycled; this requires energy. Energy is not recycled, but can be
Describe energy converted to different forms and transferred from one organism to another. Because
transfer in
consumers can’t make their own food, they obtain energy by eating as described
ecosystems
above. At the same time energy is transferred, that matter that makes up the food
molecules is transferred. So, Sun E  Producers  Consumers.
Describe the relationship between food chains A food web is made of many different food chains.
& food webs
Bottom layer = All producers (Largest layer b/c most
Distinguish the organisms present at each level energy & largest # of organisms)
of an energy pyramid
Middle layer = Herbivores
Top layer = Carnivores & Omnivores
As you move up the energy pyramid, each level becomes smaller. Only about _10_% of the energy
available at each feeding level of an energy pyramid is transferred to the next higher level.
How are
hydrothermal
vents related to
chemosynthesis?
A hydrothermal vent is a deep crack in the ocean floor through which the heat of
molten magma can escape. In the 70s, scientists discovered that communities living
around these vents were very diverse. This heated water contains nutrients, like
sulfur molecules, that bacteria use to produce their own food. Consumers that live
in the hydrothermal vent communities rely on the chemosynthetic bacteria for
nutrients and energy.