Revision sheet -2-

Grade-10-
Ecology
A) Choose the correct answer
1. The ecosystem in the diagram below has both biotic and abiotic factors.
Which is an abiotic factor in this ecosystem?
A. fish B. snails
C. plants D. sand
2. Which of these statements best describes a niche in an ecosystem?
A. the role of a species in its population
B. the role of a species in its community
C. the way a species uses the resources in its habitat
D. the way a species interacts with other species in its habitat
3. A spider hides in an orchid flower. It captures and eats insects as they enter the flower.
How could this be an example of mutualism?
A. if the spider is also eating part of the flower
B. if the spider’s actions do not affect the orchid plant
C. if the insects that the spider captures are harming the flower
D. if the insects that the spider captures are pollinating the flower
4. The diagram below shows some organisms that live in one kind of
seaside ecosystem. Which of the following organisms would benefit most
from having patterns and coloration that help them blend in with the
sand-dune grasses?
A. crab C. palm trees
B. sandpiper D.grasshopper
5. Which of the following describes a community?
A. all populations that live in the same area
B. all populations that contain the same species
C. all populations that live in the same area and interact
D. all populations that live in the same area but do not interact
6. Green plants use energy from the sun to produce food during the process of photosynthesis.
This food provides energy to an entire food chain. What starting materials do the plants use
to make this food?
A. soil and water C. carbon dioxide and water
B. water and oxygen D. water, phosphorus and nitrogen
7.Why are decomposers an essential part of a healthy ecosystem?
A. Decomposers are a necessary part of the diet of most consumers.
B. Decomposers convert plant material into a form that primary consumers can use.
C. Decomposers make resources available to producers by breaking down waste materials.
D. Decomposers extract energy from sunlight as they break down plant materials, adding
returning energy to the system.

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8.What is one way that cooperation helps lions to survive?
A. They hunt in a group to increase their likelihood of catching prey.
B. They all have a tan color that helps them blend into their environment.
C. They eat a variety of prey, including zebras, buffaloes, and wildebeest.
D. They live in prides of five to ten adult females and their young, and one or
two adult males.
9. The food web below shows some of the feeding relationships
among organisms in Arctic waters. Which organism would be
least affected by overfishing for cod in Arctic waters?
A. seals C. baleen whales
B. shrimp D. toothed whales
10.A scientist is studying a population of elephants contained in
an animal preserve. Which of the following must be true if
the size of the population is increasing?
A. The birth rate has dropped to zero.
B. The birth rate is equal to the death rate.
C. The death rate is greater than the birth rate.
D. The birth rate has become greater than the death rate.
11.Which of the following best describes what scientists consider when they study ecology?
A. the interactions of organisms with their environment
B. the interactions of organisms with weather and climate
C. the interactions of organisms to reproduce and produce offspring
D. the interactions of organisms with one another and the environment
12.Which of the following determines where a population can live?
A. whether its needs are met by the biotic factors in the habitat
B. whether its needs are met by the abiotic factors in the habitat
C. whether its needs are met by the abiotic and biotic factors in the habitat
D. whether its needs are met by the other populations of organisms in the habitat

13.The following image shows organisms in a certain land biome.

Which land biome is most likely shown in this image?
A. desert C. tropical rain forest
B. tundra D. temperate grassland

14.Which of the following is a biotic factor in an ecosystem?

A. wind C. small rocks
B. tree leaves D. light from the sun
15.Which of these statements describes a species?
A. A species is a group of organisms that are closely related.
B. A species is a group of organisms that live in the same habitat.
C. A species is a group of organisms that live in an area and interact.
D. A species is a group of organisms that are closely related and produce fertile offspring.

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16.Which of the following is an example of a biotic limiting factor in an ecosystem?
A. New predators move into the ecosystem.
B. A drought occurs for several months.
C. A hurricane passes through an ecosystem.
D. Living space is lost due to human activities.
17.Which of the following events would lead to an increase in the size of a population of
squirrels?
A. More squirrels are born than die.
B. Some squirrels emigrate in search of food.
C. New predators are added to the ecosystem.
D. A large number of squirrels die because of a forest fire.
18.A scientist creates the following graph to demonstrate the effect of limiting factors
on a population of rabbits. According to the graph, during which
year did the limiting factors in this environment most affect the
rabbit population?
A. Year 1 C. Year 3
B. Year 2 D. Year 4
19. Which statement provides an example of how social hierarchy
might influence a population?
A. Soldier termites defend the colony from predators.
B. Prairie dogs uses a high-pitched bark to communicate.
C. Mistletoe sends roots into tree branches to take in nutrients.
D. Poison tree frogs have bright colors signifying that they are toxic.
20. A scientist observes a population crash among eagles within an island ecosystem. Which
event might have led to such a crash?
A. Travelers brought new crops to the island.
B. A drop in sea level exposed more of the island.
C. The closing of a dam caused the island to flood.
D. Warm weather conditions resulted in an abundance of food.
21. Which phrase best describes the soil in a grassland biome?
A. dry and frozen
B. rocky, sandy, and dry
C. deep, dark, and nutrient rich
D. thin, acidic, and nutrient poor
22. The diagram shows a person commuting to work.
Which of the following best describes what the person is doing?

A. recycling natural resources

B. depleting natural resources

C. conserving natural resources

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 D. identifying new natural resources

23.The following table lists the number and variety of organisms in four different
ecosystems.

Animals Plants
# of Species # of Organisms # of # of
Species Organisms
4 300 5 500 Ecosystem 1
7 100 10 300 Ecosystem 2
5 200 2 100 Ecosystem 3
4 30 6 50 Ecosystem 4

Based on the table, which ecosystem is likely the most sustainable?

A. Ecosystem 1 C. Ecosystem 3
B. Ecosystem 2 D. Ecosystem 4
24.Coral reefs and kelp forests are both found in coastal ocean ecosystems. How are the
ecosystems in which they are found different?
A. Coral reefs are found in warm waters and kelp forests are found in cold waters.
B. Coral reefs are found in salt water and kelp forests are found in fresh water.
C. Coral reefs are found above the tide line and kelp forests are found below the tide line.
D. Coral reefs are found in water exposed to sunlight and kelp forests get their energy from
chemicals along the ocean floor.
25.Which term best describes a body of water that forms where a river flows into an ocean?
A. bog C. swamp
B. estuary D.wet land
26.What is one way that a temperate rain forest is different from a temperate deciduous
forest?
A. A temperate rain forest has large populations of grasses rather than tall trees.
B. A temperate rain forest is made up of palm trees rather than coniferous trees.
C. A temperate rain forest has a long rainy season rather than moderate, year-round rainfall.
D. A temperate rain forest has trees that lose their leaves in winter rather than keeping them
year-round.

27.The diagram shows an outline of Earth. At which location is a

tropical rain forest biome most likely to be located?
A. Location 1 C. Location 3
B. Location 2 D. Location 4
28.Worms break down dead plants in the soil to release nutrients.
Which property of nutrients shows that they are matter?
A. Nutrients are warm. C. Nutrients can do work.
B. Nutrients have mass. D.Nutrients contain energy.
29. In which biome would you expect to find many coniferous trees?

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A. taiga C. savanna
B. tundra D. tropical rain forest

30. What important role does fire play in a grassland biome?

A. It helps seeds germinate.
B. It spreads seeds to distant locations.
C. It causes flowers on plants to bloom.
D. It prevents animals from eating plant populations.
31. How are tropical plants such as bromeliads adapted to the biome in which they live?
A. They grow from tree branches rather than the forest floor, which helps them to absorb more
sunlight.
B. They have long, thick roots, which helps them to gather the nutrients that are found deep
within the soil.
C. They have hollow leaves and stems for storing water, which helps them to survive long periods
with little rainfall.
D. They lose their leaves during the winter, which helps them to save energy when the
temperature falls and prevents the buildup of snow.
32. How is a tundra biome similar to a desert biome?
A. Both biomes have dry, rocky soils.
B. Both biomes lack plants or animals.
C. Both biomes are hot during the day and cold at night.
D. Both biomes are characterized by very little precipitation.
33. A researcher is investigating the plants shown below. Which biome
is the researcher most likely studying?
A. taiga C. grassland
B. desert D. tropical rain forest
34. Which statement about the deep ocean zone is true?
A. Plankton dominate this zone of the ocean.
B. Coral reefs are commonly found in this zone.
C. Organisms in this zone must be able to survive major changes in salinity.
D. Some organisms in this zone use chemicals for energy rather than sunlight.
35. Which example represents an abiotic factor in an aquatic ecosystem?
A. Water lilies float on top of a pond.
B. A population of bass is living in a lake.
C. The pH of a lake is decreased by acid rain.
D. Dragonflies feed on small insects near a pond.
36. How do rivers and streams differ from lakes and ponds?
A. Rivers and streams are made up of salt water instead of fresh water.
B. Unlike the water in lakes and ponds, the water in rivers and streams flows.
C. Fish can live in rivers and streams, whereas plants grow in lakes and ponds.
D. Lakes and ponds form only after heavy rains, whereas rivers and streams always exist.
37. The illustration shows a river otter. What is one way the otter

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is adapted to living in the moving water of a river?
A. It has sharp claws. C. It has streamed lined body
B. It has long whiskers. D. It has an Earth-toned color

38. Which ocean zone is at the deepest location?

A. neritic zone C. abyssal zone
B. bathyal zone D. intertidal zone
B) Check the box to show whether each statement is true or false.

F T

1. Competition occurs when organisms try to use the same limited  

resource.

2. Biomes are characterized by temperature, precipitation, and the plant  

and animal communities that live there.

3. A habitat is the role of a population in its community, including its  

environment and its relationship with other species.

4. A food chain is the feeding relationships among all of the organisms in  

an ecosystem.

5. A limiting factor is an environmental factor that increases the growth  

of a population.