1. Observing Ecological Relationships
7th Grade FCAT 2.0 Review
Observing Ecological Relationships

2. What relationships exist in an ecosystem?
Essential Question:
What relationships exist in an ecosystem?

3. Engage:
While listening to the flea story try to identify as many relationships among organisms as possible
A Flea’s Story
I loved living in the mane of the regal, warm-blooded beast. Together we surveyed our kingdom, the Serengeti. The season of rains was upon us, renewing the parched land and refilling the waterholes. The rains brought the prey. How I enjoyed the hunt.

4. Engage:
We crouched low in the grasses and watched. Herds of zebra grazing in the distances enticed my hungry host. We moved closer, but the birds that were eating ticks from the zebra’s hides screeched a warning as they took flight. In a flash of white and black stripes, dinner vanished. How I despised those birds.

5. Engage:
A breeze rolled across the high grasses like an unseen hand, providing momentary relief from the day’s heat. Across the plain, gazelles were grazing their way toward us. This time, we were downwind and well-hidden. To prepare for the chase to come, I sank my mouthparts deep into my host’s flesh. I knew my host was studying the gazelles, noting the young and old. They would be the easiest to catch. Her muscles tensed. One slow step forward…then another…and the chase was on with a fire bolt of speed.

6. Engage:
The kill was quick. My host was soon enjoying her victory, and in time, I would benefit too. I spotted a pack of hyenas nearby. I supposed they hoped to scavenge a few scraps later in the day. The worms would take what was left.

7. Explore:
Create a food web with the organisms in the flea story.
An arrow should be pointing from the organism that is providing the energy TO the organism that receives the energy.
Example:

8. Explore: lion lion birds birds gazelle gazelle flea flea hyena zebra
tick
tick
worms
worms
grass
grass

9. Explain: Use the food web and terms to fill in the chart.
Producer- makes its own food
Consumer-gets food by eating other organisms
Decomposer-gets its food from the remains or waste of other organisms
Producer(s)
Consumer(s)
Decomposer(s)
Predator(s)
Prey
worms
worms
lion
zebra
grass
gazelle
gazelle
hyena
lion
zebra
flea
birds
tick

10. Elaborate:
An ________ is all the organisms that live in an area together with the __________ factors of the environment.
ecosystem
Non living

11. Elaborate:
For any population in an ecosystem to thrive, there must be enough food, water and living space.

12. Elaborate:
Such factors are called _________ because they limit how many organisms can live in an environment.
Other limiting factors include shelter, _________, parasitism, predation and ___________.
Limiting factors
disease
Nesting sites

13. Elaborate:
Different __________, or kinds, or organisms living together interact with one another.
The relationships they form can be divided into three main categories.
species

14. Elaborate:
_________ occurs whenever more than one individual or population tries to make use of the same limited resource.
Competition

15. Elaborate:
_______ is a type of feeding relationship in which one animal, the ___________, captures and eats another animal, the __________.
Predation
predator
prey

16. Elaborate: _________ is a close relationship between two species.
There are 3 types of symbiosis.
Symbiosis

17. Elaborate: ________ is a relationship that benefits both species.
Mutualism

18. Elaborate: ________ benefits one species while the other is unaffected
Commensalism

19. Elaborate:
________ is a relationship that benefits one species and harms the other.
parasitism

20. Elaborate:
Some other examples include mutualism between a clown fish and a sea anemone because the fish gets protection and the anemone gets scraps of food from the fish.

21. Elaborate:
Commensalism between a shark and remora fish because the remora gets food and the shark is unaffected.

22. Elaborate:
Parasitism between mistletoe and a tree because the mistletoe get nutrients from the tree and the tree loses nutrients.

23. Elaborate:
All of the organisms in an ecosystem need _________ to live.
Organisms get energy from food in different ways depending on the type of organism they are.
energy

24. Elaborate:
__________, such as plants, make their own food using the energy of the sun and raw materials from the environment.
Producers are the most plentiful organism in any ecosystem.
producers

25. Elaborate:
________ get food by eating other organisms including herbivores that eat only plants, carnivores that eat only animals, and omnivores that eat both.
Consumers

26. Elaborate:
The top consumer of an ecosystem, known as the ______________, will have the fewest individuals.
If there were too many predators, then the food supply would run out.
Apex predator

27. Elaborate:
_________ get their energy from the remains or waste of other organisms.
Many bacteria and fungi are decomposers.
Decomposers

28. Elaborate:
Scientists often use a _____________ to show the flow of energy in an ecosystem from producers, to consumers, to decomposers.
Food web

29. Evaluate: Use evidence from this lesson to answer
What symbiotic relationships exist in the flea story?
Describe a river ecosystem. Include several relationships that exist and any limiting factors.
Mutualism- zebra and bird (zebra gets ticks removed, bird gets meal
Commensalism-hyena and lion (hyena gets scraps, lion gets nothing
Parasitism-lion /flea and zebra/tick
The Silver River ecosystem includes alligators, fish, water plants, birds and turtles. Relationships include predator prey with the alligator and anything it wants to eat, and competition among birds for food. A limiting factor might include the amount of food and nesting sites for birds.