8th Grade Science Unit Review
Name:
Teacher:
Date:
Each student should be able to:
8.11(A) Describe producer/consumer, predator/prey, and parasite/host relationships as they occur in food
webs within marine, freshwater, and terrestrial ecosystems.
8.11(B) Investigate how organisms and populations in an ecosystem depend on and may compete for biotic and
abiotic factors such as quantity of light, water, range of temperatures, or soil composition.
8.11(C) Explore how short- and long-term environmental changes affect organisms and traits in subsequent
populations.
8.11(D) Recognize human dependence on ocean systems and explain how human activities such as runoff, artificial
reefs, or use of resources have modified these systems.
Marine Food Web
1. In the marine food web to the right, color the
producers green.
2. List the 3 producer/consumer relationships
from the food web to the left. Draw a green
circle around these organisms.
3. List 3 predator/prey relationships from the
marine food web. Draw a red circle around
these organisms.
4. Trichodina, a parasite, feeds on the skin of the
gills of living fish. This damages the fish gills
and causes fish to take in less oxygen. Add
Trichodina to the food web. Make sure your
arrow is showing the direction of energy flow!
All animals in a food web get energy directly or indirectly from what organism?
What organism provides a significant amount of oxygen to the atmosphere?
8.11(B) Investigate how organisms and populations in an ecosystem depend on and may compete for biotic and
abiotic factors such as quantity of light, water, range of temperatures, or soil composition.
Biotic Factors
Abiotic Factors
Bio means-
Prefix “a-” means
Definition-
Definition-
Example-
Example-
Example-
Example-
From the marine food web on page 1, which organism competes most with the heron? Why?
As the amount of biotic and abiotic factors goes down, what happens to the level of competition within
an ecosystem? Why?
Use the Venn Diagram below to show how long-term and short-term environmental changes affect
organisms and traits populations in later generations.
Short-Term
Long-Term
Environmental Changes
Environmental Changes
Describe how humans depend on ocean systems.
Describe how pollution impacts ocean systems.
How does a dead zone form? Draw and label to illustrate the formation of a dead zone.
Fertilizers are
used on crops
on farms all
over the
country.
Runoff from
streams and
rivers is filled
with fertilizer
and other
pollution. This
runoff flows
into the
ocean.
Fertilizer in
the ocean
water causes
phytoplankton
and other
aquatic plants
to grow at
high rates.
Phytoplankton
, algae, and
other aquatic
plants die. As
these dead
plants
decompose
oxygen is
removed from
the ocean.
Illustration: How a dead zone forms…
What is an artificial reef? How do artificial reefs modify ocean ecosystems?
What impact does overfishing have on ocean ecosystems?
There is not
enough
oxygen
availiable for
any living
things in the
ocean.