Download Ecological Interactions Study guide

Ecological Interactions
Study guide
Adapting to the Environment (pg 662)
1. What is an ecosystem?
An ecosystem is all the living and nonliving things that interact in an area.
2. True or False: Every organism in an ecosystem has a variety of adaptations that are suited to its
specific living conditions.
3. List the three types of adaptations
a. behavior
b. physical characteristics
c. structural
4. An organism’s particular role in an ecosystem is its niche
5. A niche includes:
a.
Type of food an organism eats
b.
How it obtains its food
c.
When and how the organism reproduces
d.
Physical conditions required to survive
6. Complete the concept map:
7. What is competition?
The struggle between organisms to survive in a habitat with limited resources.
8. What happens when two organisms are competing for the same niche?
One will eventually die off.
9. True or false? Some species of birds avoid competition by feeding in different parts of trees.
10. How do some organisms survive in an ecosystem when there is competition?
They have adaptations that enable them to reduce competition. Examples: chemicals or
different dietary specializations.
11. How do adaptations enable organisms to reduce competition for food and other resources?
Adaptations create a unique niche that is not shared by organisms of another species, thus
reducing competition for resources between species.
12. What are two adaptations that prey organisms have developed to protect themselves? Describe how
each adaptation protects the organism.
Camouflage—the more an organism resembles its surroundings, the less likely it is that a predator will
notice it.
False coloring—a predator may mistake the markings for a different or larger organism or for another
predator.
13. Compare and contrast predation and symbiosis. What is predation? What is symbiosis? How are they
alike? How are they different?
 Predation is an interaction where one organism hunts & kills another for food.

Symbiosis is a close relationship between two species that benefits at least one of the
species.

Predation & symbiosis are similar because they both interact with other organisms and
at least one organism benefits.

Predation & symbiosis are different because predation is where one organism kills the
other for food. There are three types of symbiosis. One type hurts the host organism,
one does not affect the other organism, and one benefits the other organism.
14. Name and describe the three types of symbiotic relationships
a.
Mutualism –both species benefit
b.
Commensalism – one species benefits & the other is neither helped nor harmed
c.
Parasitism – one organism lives on or in another organism and harms it
In 1997, a community decided to get rid of the population of rattlesnakes in the area. The graph below
shows what happened to the populations of rattlesnakes, birds, and rodents. (The rodents included
animals such as mice, rats, and prairie dogs.)
15. Did the bird population appear to benefit from the elimination of rattlesnakes? How do you know?
No, the bird population continued to decline.
16. Did the rodent population appear to benefit from the elimination of the rattlesnakes? How do you know?
Yes. The rodent population increased after the rattlesnakes were eliminated.
17. What was the main source of food for the rattlesnakes? How can you tell?
Rodents. When rattlesnakes were eliminated, the rodent population increased.
18. Why do you think the bird populations decreased sharply after the rattlesnakes were eliminated?
There were more rodents to eat the bird’s eggs.
19. Do you think it was a good idea for the community to eliminate the rattlesnake population? Explain your
answer.
Answers will vary.
My opinion is NO, because the rattlesnakes help keep the rodent population naturally in
balance (without assistance of chemical poisons).
20. A shark catches a young albatross; the shark is the predator and the albatross is the shark’s prey.
21. Claws and sharp teeth are adaptations of predators.
22. When the death rate exceeds the birth rate in a population, the size of the population usually declines
23. Complete the cycle diagram by filling in the blanks with increases or decreases.
decreases
decreases
24. The organisms that a parasite lives on is its host
25. Biotic vs. Abiotic Factors – If a factor is changed or removed, how does it impact the other resources
or organisms in the ecosystem?
The change or removal impacts the availability of other resources within the ecosystem.
Example--Changing/removing a factor could remove a food source or remove a
predator. Populations could either overgrow the habitat’s resources or could starve.
26. Identify the following organisms from the
marine food web:
a. Producers:
i. dinoflagellates
ii.
diatoms
iii.
Coralline algae
iv. Bull kelp
b. Herbivores
i. euphausid
ii.
sweep
iii.
Water flea
iv.
Sea urchin
c. Carnivores
i. blenny
ii. pilchard
iii. crab
iv. snapper
vi.octopus
vii.dolphin
viii.tiger shark
v. yellow-eye mullet
d. Which organisms are in competition?
Blenny & pilchard; water flea, sweep & euphausid; tiger shark & dolphin; octopus
& yellow-eye mullet, snapper & yellow-eye mullet
e. Draw a diagram with arrows showing where the energy comes from, ending with the
decomposers.
SUN  producer  consumer  decomposer
f.
Which organism transfers the most energy to the next level? producer
g. If we removed the snapper from the food chain, what affect would that have on
the other organisms?
There would be an increase in the pilchard fish. The yellow-eye mulled might
increase because they would have more blenny to eat.
27. What is the difference between marine and freshwater ecosystems?
--freshwater --Animal & plant life are unable to adapt to higher levels of salt
-- Marine --Struggle to maintain diversity due to human activity. Oceans are the largest ecosystems with biodiversity
the greatest in warm waters.