Download Ecology - Review

LIBERTY HIGH SCHOOL
LIVING ENVIRONMENT 2
Name: ________________________________________Period ________ Date ________________
Ecology - Review
1. Abiotic factors and Biotic factors

Biotic Factors: Living things (prefix 'Bio' means life).
Examples: Plants, animals, fungi, Protists and bacteria are all biotic factors.

Abiotic Factors: Non-living things (prefix 'A' meaning opposite of prefix 'bio').
Examples: temperature, rain, snow, hurricanes, and rocks, are abiotic factors.
Practice 1
In an ocean, the growth and survival of seaweed, small fish, and sharks depends on abiotic factors such as
A) sunlight, pH, and type of seaweed
C) number of herbivores, carbon, and food
B) sunlight, temperature, and minerals
D) number of decomposers, carbon dioxide, and nitrogen
2. Food Chain & Food Web

Autotrophs or Producers: organisms that make their own food from inorganic substances.
o “Auto” means “itself” and “trophs” means “to eat”
o Examples: plants (trees, bushes, ferns, etc.) and some bacteria

Heterotrophs or Consumers: organisms that eat other organisms.
o “Hetero” means “others” and “trophs” means “to eat”
o Example: animals, fungi, protozoa or protist, some bacteria
Practice 2.1.
Identify one abiotic factor that would directly affect the survival of
organism A shown in the diagram below.

Primary Consumers or Herbivores: organisms (heterotrophs or
consumers) that eat only producers.
o Examples: Grasshoppers, cows, deer, and rabbits.

Secondary Consumers or Carnivores: organisms (heterotrophs or
consumers) that eat other animals.
o Examples: Snakes, frogs, raccoons, and hawks.

High Level Consumers: organisms (heterotrophs or consumers) that eat secondary consumers
o Examples: eagles, sharks, lions, owls, snakes, and lizards.

Decomposers: Organisms (heterotrophs or consumers) that consume dead organisms and organic wastes.
o They break down organic molecules into inorganic molecules: water, carbon dioxide, and minerals.
o They recycle dead organisms.
o Examples: bacteria and fungi.
Ecology
Abiotic Factors
Water, temperature
Biotic Factors
Animals and plants
Heterotrophs
Animals, Fungi, Protozoa, bacteria
Primary Consumers or
Herbivores
Cows, deer
Secondary Consumers
or Carnivores
Frogs, wolves
High Level Consumers
Eagle, Snake
Autotrophs
Plants, some bacteria
Decomposers
Fungi, bacteria
Practice 2.2:
In the diagram to the right, what does X most likely represent?
A) decomposers
B) herbivores
C) carnivores
D) autotrophs
2. Food Chain & Food Chain



A diagram that represents the relationships between prey and predator.
The path in an ecosystem through which food passes
A sequence of organisms showing who eats whom.
Producer
Autotrophs
Primary Consumer
Herbivore
Heterotrophs
Secondary Consumer
Carnivore
Heterotrophs
High Level Consumers
Carnivore
Heterotrophs
Decomposer
Heterotrophs
Practice 3:
3.1. A food chain is represented below. This food chain contains
A) 4 consumers and no producers
C) 2 predators, 1 herbivore, and 1 producer
B) 1 predator, 1 parasite, and 2 producers
D) 2 carnivores and 2 herbivores
3.2. Using one or more complete sentences, predict how one of
the populations in the food web will most likely change if the
rabbit population increases over a period of 3 years.
4. Cycle of Matter


The atoms and molecules on the Earth cycle among the living and nonliving components of the biosphere. For
example, carbon dioxide and water molecules used in photosynthesis to form energy-rich organic compounds
are returned to the environment when the energy in these compounds is eventually released by cells.
Cycle of water, cycle of carbon, cycle of CO2 and O2, and cycle of nitrogen.
Practice 4:

A student uses a covered aquarium to study the interactions of biotic
and abiotic factors in an ecosystem. The aquarium contains sand,
various water plants, algae, small fish, snails, and decomposers. The
water contains dissolved oxygen and carbon dioxide, as well as tiny
amounts of minerals and salts.

Explain how oxygen is cycled between organisms in the ecosystem
described in the paragraph.
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
In the aquarium, what happens to the atoms of certain chemical elements such as carbon, oxygen, and nitrogen?
A) They are never found in living systems.
B) They move into living systems and remain there.
C) They move into and out of living systems.
D) They move out of living systems and never return.
5. Flow of Energy
 Energy flows through ecosystems in one direction, typically from the Sun, through photosynthetic organisms
including green plants and algae, to herbivores to carnivores and decomposers.
Energy Pyramid
 Continual input of energy from sunlight keeps the process going. This concept may be illustrated with an energy
pyramid.
 10 percent of the energy moves from one level to another, 90 percent is lost as heat or used up in metabolic
activities.
Practice 5
5.1. Four students each drew an illustration to show the flow of energy in a field ecosystem. Which illustration is
most accurate?
5.2. The diagram to the right represents an energy pyramid.
At each successive level from A to D in the energy pyramid, the amount of available energy
A) remains the same
B) increases, then decreases
C) increases, only
D) decreases, only
5.3. Which statement about the energy pyramid shown is correct?
A) The total amount of energy at level D is less than the total amount of energy at level B.
B) The amount of energy is identical in each level of the pyramid.
C) The total amount of energy decreases with each successive feeding level from D to A.
D) The amount of energy needed to sustain the pyramid enters at level D.
6. Niche & Habitat
 Habitat: the area where an organism lives.
 Niche: the role of an organism in the ecosystem
o Its place in the food web, the type of food the organism eats, how it obtains the food, which other
species use this organism as food, when and how it reproduces, the range of temperatures that the
organism needs to live.
 Two species cannot share the same habitat and have the same niche.
 Two species can share the habitat if they have different niches.
 Two species can share the same niche in different habitats.
Practice 6
6.1. Two closely related species of birds live in the same tree.
Species A feeds on ants and termites, while species B feeds on
caterpillars. The two species coexist successfully because
A) they use different methods of reproduction
B) they interbreed
C) each occupies a different niche
D) birds compete for food
6.2. The feeding niches of three bird species are shown in the diagram. What is the advantage of these different
feeding niches for the birds?
A) less competition for food
B) fewer biotic resources for each bird species
C) fewer abiotic resources for each bird species
D) less energy available as the birds feed higher in the tree
7. Community Interaction in an Ecosystem
Relationships between organisms may be negative, neutral, or positive. Some organisms may interact with one
another in several ways. They may be in a producer/consumer, predator/prey, or parasite/host relationship; or
one organism may cause disease in, scavenge, or decompose another.

Competition: organisms of the same of different species attempt to use an ecological resource in the same
place at the same time.
o No two species can occupy the same niche in the same habitat at the same time.
 Predation: one organism captures and feeds another organism
o Predation: the organism that does the killing. Example: impala
o Prey: the food organism. Example: cheetah
 Symbiosis: two species live closely together
o Mutualism: both species benefit from the relationship
o Example: many flowers depend on certain species of insects to pollinate them
o Commensalism: one member of the association benefits and the other is neither helped nor harmed
o Example: small marine animals called barnacles, attach themselves to a whale’s skin
o Parasitism: one organism lives on or inside another organism and arms it (parasite)
o Examples: fleas, tapeworms, ticks, and lice obtain nutrients from another organism (host)
 Scavengers: carnivores that feed on dead animals that they find
o Examples: vulture, hyenas, raccoons.
 Omnivores: animals that feed on both plants and animals
o Examples: humans, bears, and pigs.
Practice 7
7.1. Many species of plants interact with harmless underground fungi. The fungi enable the plants to absorb
certain essential minerals and the plants provide the fungi with carbohydrates and other nutrients. This
describes an interaction between a
A) scavenger and a decomposer
B) producer and a consumer
C) parasite and its host
D) predator and its prey
7.2. Salmonella bacteria can cause humans to have stomach cramps, vomiting, diarrhea, and fever. The
effect these bacteria have on humans indicates that Salmonella bacteria are
A) predators
B) parasitic fungi
C) pathogenic organisms
D) decomposers
8. Stability of an Ecosystem
 As a result of evolutionary processes, there is a diversity of organisms and roles in ecosystems. This
diversity of species increases the chance that at least some will survive in the face of large environmental
changes. Biodiversity increases the stability of the ecosystem.

Biodiversity also ensures the availability of a rich variety of genetic material that may lead to future
agricultural or medical discoveries with significant value to humankind. As diversity is lost, potential
sources of these materials may be lost with it.

The following factors make the ecosystem more stable: Biodiversity, Genetic Variation, Cycle of Matter,
and Flow of Energy
Practice 8
8.1. A greater stability of the biosphere would most likely result from
A) increased deforestation
B) decreased consumer populations
C) increased biodiversity
D) decreased finite resources
8.2. The diagram represents an energy pyramid constructed from data
collected from an aquatic ecosystem. Which of the following statements
best describes this ecosystem?
A) Long-term stability of this ecosystem will continue.
B) The herbivore populations will continue to increase in size
for many years.
C) The ecosystem is most likely unstable.
D) The producer organisms outnumber the consumer organisms.
8.3 Which statement describes a situation that leads to stability within an ecosystem?
A) Carbon dioxide and water are released only by abiotic sources in the ecosystem.
B) Interactions between biotic and abiotic components regulate carbon dioxide and water levels.
C) Organisms provide all the necessary energy for the maintenance of this ecosystem.
D) Animals provide the oxygen used by plants, and plants provide the nitrogen needed by animals.
9. Carrying Capacity & Limiting Factors
 Carrying Capacity
The number of organisms any habitat can support (carrying capacity) is limited by the available energy, water,
oxygen, and minerals, and by the ability of ecosystems to recycle the residue of dead organisms through the
activities of bacteria and fungi.
 Limiting Factor
In any particular environment, the growth and survival of organisms depend on the physical conditions including
light intensity, temperature range, mineral availability, soil/rock type, and relative acidity (pH).
Practice 9
9.1. The growth of a population is shown in the graph. Which
letter indicates the carrying capacity of the environment for
this population?
A)A
B) B
C) C
D) D
9.2. What impact do the amounts of available energy, water,
and oxygen have on an ecosystem?
A) They control environmental temperature.
B) They act as limiting factors.
C) They recycle the residue of dead organisms.
D) They are used as nutrients.
9.3. Ten breeding pairs of rabbits are introduced onto an island with no natural predators and a good
supply of water and food. What will most likely happen to the rabbit population?
A) It will remain relatively constant due to equal birth and death rates.
B) It will decrease and then increase indefinitely.
C) It will die out due to an increase in the mutation rate.
D) It will increase until it exceeds carrying capacity
10. Ecological Succession
Through ecological succession, all ecosystems progress
through a sequence of changes during which one ecological
community modifies the environment, making it more suitable
for another community. These long-term gradual changes result
in the community reaching a point of stability that can last for
hundreds or thousands of years.
A stable ecosystem can be altered, either rapidly or slowly, through the activities of organisms (including humans),
or through climatic changes or natural disasters. The altered ecosystem can usually recover through gradual changes
back to a point of long term stability.
Practice 10
10.1. Which concept is represented in the graph?
A) cycling of carbon and nitrogen in a forest
B) ecological succession in a community
C) energy flow in a food chain over time
D) negative human impact on the environment
10.2. In December 2004, a tsunami (giant wave) destroyed many of the marine organisms along the coast of the
Indian Ocean. What can be expected to happen to the ecosystem that was most severely hit by the tsunami?
A) The organisms in the ecosystem will become extinct.
B) The ecosystem will change until a new stable community is established.
C) Succession will continue in the ecosystem until one species of marine organism is established.
D) Ecological succession will no longer occur in this marine ecosystem.