DISD CA 8 Science Unit 08 2015-16

DISD CA 8 th Science Unit 08
(8.11A & 8.3B)
How many organisms in the Food Web below eat only producers?
Record your answer and fill in the bubbles on your answer document. Be sure to use the correct place value.
Zooplankton are small animals that form the base of marine ecosystems. Baleen whales eat zooplankton
by taking a large amount of water into their mouth. These whales use special structures in their mouth to
separate zooplankton from the water. Because baleen whales eat zooplankton, they are classified as –
A. producers
B. predators
C. parasites
D. hosts
(8.11A) What
interaction between organisms would be described as parasitic?
a mosquito feeding on the blood of a dog
a bee gathering nectar and pollen from a flower
a cleaner shrimp picking dead skin off a large fish
a nonpoisonous snake mimicking a poisonous snake
The diagram below shows a food web for a community.
Which organisms are in a predator/prey relationship?
butterflies and flowers
flowers and grasses
grasshoppers and mice
coyote and mice
(8.11B) Use
the information table below and your knowledge of science to answer the following question.
Australian Animal Ranges and Food Sources
Red Kangaroo
Desert areas
Throughout central and
northern Australia
Dorre and Bernier Islands
which are off the coast of
Western Australia
Bushland areas – both
coastal and inland
Insects, seeds, bulbs,
fruit and fungi
Wide range of
vegetation including
grass, leaves, and crops
Herbs, grasses, seed
husks, seed, and bulbs
Eucalyptus leaves
Which of these species would be most in danger of becoming extinct if one of their food sources becomes
A. Bilbie
B. Red Kangaroo
C. Mala
D. Koala
(8.11B & 8.3B)
Which organisms in the Food Web below compete for the same food source in this environment?
Grasshoppers and snakes
Hawks and frogs
Frogs and snakes
Decomposers and grasses
(8.11B & 8.2E) The
Couch’s Spadefoot lives in Texas and has the characteristics listed below.
The Couch’s Spadefoot is adapted to a certain type of environment. Which of these resources is most likely
limited in this environment?
A. Soil
B. Sunlight
C. Water
D. Oxygen
(8.11B) A
park is home to a large number of robins, squirrels and rabbits. The robins and squirrels live in the park’s
trees. The robins feed on earthworms and insects that live on the ground. The squirrels eat the acorns produced
by the park’s oak trees. The rabbits hide in the bushes and feed on the grass. Which factor would directly limit
the number of rabbits that could live in this park?
A. number of robins
B. number of bushes
C. number of acorns
D. number of squirrels
Wild Soay sheep live in a cold environment on a small Scottish island. The sheep used to be large
because they gained extra weight during the summers in order to survive the harsh winters. A recent change in
the island’s climate has caused grass to be available for a longer period each year, so survival conditions for the
sheep have become less challenging.
Marcus applies a small amount of liquid between his dog’s shoulder blades each month. The liquid helps
prevent insects from bothering his dog. Lately, the liquid does not keep fleas off his dog. What is the likely
cause of this change?
A. The fleas that survived exposure to the liquid once have produced offspring that are resistant to the
B. The weather conditions have changed. There are more fleas living in Marcus’s yard.
C. The liquid has changed the dog’s fur over time. Now the liquid is absorbed into the fur rather than
staying on the skin.
D. The fleas are using the liquid as a food source.
(8.11C & 8.3A)
Researchers who study these sheep have most likely observed a decrease in the wild Soay’s –
A. size
B. life expectancy
C. reproduction rates
D. body temperature
The Guam rail is a flightless bird found on the island of Guam. It builds a shallow nest on the ground and
lays eggs throughout the year. There are no native species of snakes on Guam, so the Guam rail had no
experience with snake predators until the brown tree snake was accidentally introduced sometime between
1944 and 1952. These snakes, which eat a wide variety of animal species, quickly established a large population
on Guam.
How was the Guam rail most likely affected by the introduction of the brown tree snake?
The brown tree snake ate only species that lived in trees, so it had no effect on the Guam rail.
The Guam rail quickly developed the ability to fly in order to escape from the brown tree snake.
The population of the Guam rail declined, and the species nearly became extinct.
The Guam rail began to build its nests in trees.
Some scientists studying aquatic plants notice that flooding often leads to a decrease in the rate of
photosynthesis among aquatic plants. Flooding causes more sediment to be suspended in the water.
The increased sediment concentration decreases the amount of light that reaches the plants.
Why does a decreased rate of photosynthesis lead to a decrease in a plant population?
A. Less water is available for absorption.
B. Less tissue is available for plant growth.
C. Less energy is available for reproduction.
D. Less soil is available for leaf development.
In a Food Web, the numbers of each organism typically exist in a relatively stable proportion.
If an oil spill killed a large amount of zooplankton, what would be the next thing that would happen?
The number of tiger sharks would decrease.
The number of phytoplankton would decrease.
The number of clams, mackerels, and jellyfish would decrease.
The number of herring, whelk, squids, and loggerhead turtles would increase.
Many small island communities are dependent upon fishing in the waters around them. As humans have
advanced their technology, they have gained the ability to be more successful at fishing. Recently, the
communities have had a hard time catching fish, even with the great technology. Why is this occurring?
A. The fish have adapted to the new fishing technologies.
B. The fish population has decreased because of overfishing.
C. The fish have migrated to get away from the technology.
D. The fish population that remains is camouflaged to the technology.
(8.11D. 8.2E)
Farmers recently have started to use a lot of fertilizer on farms. Extra fertilizer runs off the farms, into the
rivers, and out into the oceans. Which of the following would be a likely outcome of this?
A. Animals will use the fertilizer to grow.
B. Kelp on the bottom of the ocean will grow.
C. Coral reefs will grow faster.
D. Algae will grow, causing algae blooms.
The chart below illustrates the type and number of items collected during a clean-up of a beach.
Based on the chart, what approximate percentage of the total items result from the action of people?