Download Ecology Study Guide KEY

8th Grade Science
Ecology Study Guide
1. What are herbivores?
Consumers that eat only plants
2. Use these animals to create a food chain. Be sure your food chain begins with the producer. (frog,
grasshopper, snake, grass)
Grass grasshopper frog  snake
3. In a food chain, what function do bacteria and fungi serve?
They are decomposers. They break dead materials and recycle their nutrients back into the
environment.
4. In the diagram below, what term(s) could be used to describe the rabbit? List all that could apply.
Consumer, herbivore, heterotroph
5. What do we call the organisms that make the energy of the Sun available for all other organisms?
Producers or autotrophs
Which organism(s) in the diagram in number 4 accomplish this task?
The plants at the bottom (lady slipper, Canada violet, Canada goldenrod)
6. What do we call all of the interconnected food chains in an ecosystem?
A food web
7. Which is a better representation of the feeding relationships in an ecosystem, a food chain or a
food web?
A food web
8. Which organisms can be predator and prey---------plants or animals? Only animals
9. What are scavengers?
They are consumers that eat dead animals.
10. Heterotrophs are organisms that have to eat other organisms to survive. Which organisms below
are heterotrophs?
BIRD CAT SQUIRREL BEAR
Flower
tree
bird
cat
squirrel
algae
bear
11. Autotrophs are organisms that can make their own food. Which organisms below are
heterotrophs?
FLOWER TREE ALGAE
Flower
tree
bird
cat
squirrel
algae
bear
12. Which terms could be used to describe the organisms in the picture below?
Herbivore (mouse) carnivore (cat) heterotroph prey (mouse) predator (cat) consumer
herbivore
carnivore
heterotroph autotroph
prey predator
producer
consumer
13. The graph below shows the relationship between two populations of organisms. One line
represents the predator population and one line represents the prey population. Which line
represents each? Explain why.
Population 1 is the predator population and Population 2 is the prey population. I know this
because the prey population (line 2) goes up ahead of the predator population (line 1). This is
because, when the prey population gets big, the predators have a lot to eat so the predator
population then goes up too. Then, when the prey population goes down, then the predator
population goes down too because they don’t have as much to eat.
Pop 1
Pop 2
14. The picture below represents all of the living and nonliving things in an environment? What is
the term for this? ECOSYSTEM
15. List the following ecological levels of organization from smallest to largest:
population, biosphere, ecosystem
Smallestpopulation, ecosystem, biosphere  Largest
16. Match the terms from the list below that mean the same thing. Then tell what each means.
autotroph
consumer
producer
heterotroph
Autotroph and producer are the same thing. They both make their own food.
Consumer and heterotroph are the same thing. They both have to eat other things to get food.
17. You find a tick on your dog’s back. The tick and your dog have a type of symbiotic relationship
with each other called parasitism. In this relationship, who is the parasite? The tick
How is the parasite affected? The parasite benefits because it gets food and a place to live.
Who is the host? The dog
How is the host affected? The host is harmed because it loses blood which makes it weaker and
possibly sick.
18. In your intestines, you have bacteria living. These bacteria get nutrients from the food you eat. In
return, these bacteria produce nutrients for you that your body cannot make on its own, such as
Vitamins B and K. What kind of symbiotic relationship do you and these bacteria have? Explain.
This symbiotic relationship is mutualism. Both organisms benefit in this relationship. The
bacteria get nutrients from my food and I get vitamins from the bacteria.
19. Where does all energy for living things on Earth come from?
The Sun
20. Which is not a likely relationship to be found in an ecosystem?
a. Predator-prey
b. Producer-consumer
c. Parasite-host
d. Consumer-consumer*******
21. Many tropical rainforests are being cut down for lumber. Describe a problem with this.
This is destroying many animals’ habitats (places to live), which could kill the animals and
cause them to go extinct. Also, a lot of medicines come from plants and animals in the
rainforest. There may be medicines there we haven’t discovered yet and will never discover if
we cut down all of the rainforests.
22. What is a population?
A group of animals of the same species
23. Put a check by the biotic factors that characteristic of a desert. Put a star by the abiotic factors
that are characteristic of a desert.
Very hot days and very cold nights ***
High amounts of precipitation
Longer days than other biomes
Nutrient rich soil
Cacti 
Lizards 
Low amounts of rainfall ***
Hot summers and cold winters
24. In what biome could the food web above be found?
A desert
25. If the mountain lion population decreased significantly due to overhunting, what would happen to
the shrub population over a period of time?
The shrub population would go down because, with less mountain lions to eat the cottontails,
there would be more cottontails to eat the shrubs, so the shrub population would go down.
26. What do decomposers do for this food web?
They break down the dead plants and animals and recycle their nutrients back into the soil.
27. Pick a carnivore in the food web and write out the food chain that it is part of.
Many different answers.
Examples:
Mojave Yuccajack rabbitcoyote (carnivore)
Mojave Yuccajack rabbitmountain lion (carnivore)
Mojave Yuccajack rabbitMojave rattlesnake (carnivore)