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Grade 7 - EOT Part 1

Total questions: 150

Worksheet time: 1hrs 15mins

Name
Class
Date
1.

Which is the best explanation of the change in energy ?

a)

New energy is produced by plants during photosynthesis.

b)

Large amounts of energy are released into the environment during photosynthesis.

c)

Energy from sunlight is destroyed as it powers photosynthesis.

d)

Energy input from the environment is stored in food molecules during photosynthesis.

2.

Which form of energy powers photosynthesis?

a)

Chemical energy

b)

Electrical energy

c)

Light energy

d)

Heat energy

3.

What two substances enter the leaf for photosynthesis to occur?

a)

Oxygen and sugar

b)

Carbon dioxide and water

c)

Oxygen and sunlight

d)

Sugar and chlorophyll

4.

What two products are released by the plant after photosynthesis?

a)

Water and carbon dioxide

b)

Sugar and oxygen

c)

Light and carbon dioxide

d)

Energy and water

5.

Where does the energy for photosynthesis come from?

a)

The soil

b)

The air

c)

The Sun

d)

The roots

6.

What type of energy transformation happens during photosynthesis?

a)

Heat → Light

b)

Light → Chemical

c)

Chemical → Electrical

d)

Sound → Chemical

7.

Which gas is released during photosynthesis?

a)

Carbon dioxide

b)

Nitrogen

c)

Oxygen

d)

Hydrogen

8.

The sugar made by the plant during photosynthesis is mainly used for:

a)

Reproduction

b)

Energy and growth

c)

Absorbing sunlight

d)

Producing oxygen

9.

Which of the following best describes the role of chlorophyll in photosynthesis?

a)

It absorbs water.

b)

It transports oxygen.

c)

It captures light energy from the Sun.

d)

It stores glucose.

10.

Which of the following shows the correct photosynthesis equation?

a)

CO2+O2H2O+C6H12O6CO_2 + O_2 \rightarrow H_2O + C_6H_{12}O_6

b)

H2O+O2CO2+C6H12O6H_2O + O_2 \rightarrow CO_2 + C_6H_{12}O_6

c)

6CO2+6H2OC6H12O6+6O26CO_2 + 6H_2O \rightarrow C_6H_{12}O_6 + 6O_2

d)

C6H12O6+6O26CO2+6H2OC_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O

11.

Which of the following are the reactants in photosynthesis?

a)

Carbon dioxide and water

b)

Oxygen and sugar

c)

Sugar and carbon dioxide

d)

Water and oxygen

12.

Which of the following are the products of photosynthesis?

a)

Water and carbon dioxide

b)

Sugar and oxygen

c)

Oxygen and carbon dioxide

d)

Water and sunlight

13.

In photosynthesis, carbon dioxide and water react in the presence of _____ to form sugar and oxygen.

a)

Carbon

b)

Heat

c)

Light energy

d)

Nitrogen

14.

Which statement correctly describes the relationship between reactants and products in photosynthesis?

a)

Products and reactants are the same substances.

b)

Reactants (CO2 and H2O) combine using light energy to produce sugar and oxygen.

c)

Products (CO2 and H2O) are broken down using light energy to produce sugar and oxygen.

d)

Reactants are sugar and oxygen, and products are carbon dioxide and water.

15.

Explain the process of chemical reactions such as photosynthesis and/or cellular respiration. Where does photosynthesis take place in plant cells?

a)

In the nucleus

b)

In the chloroplasts

c)

In the mitochondria

d)

In the cytoplasm

16.

Explain the process of chemical reactions such as photosynthesis and/or cellular respiration. Which part of the plant mainly performs photosynthesis?

a)

Roots

b)

Stem

c)

Leaves

d)

Flowers

17.

Explain the process of chemical reactions such as photosynthesis and/or cellular respiration. What cell structure contains chlorophyll and captures sunlight for photosynthesis?

a)

Mitochondrion

b)

Chloroplast

c)

Cytoplasm

d)

Vacuole

18.

Explain the process of chemical reactions such as photosynthesis and/or cellular respiration. In which parts of the cell does cellular respiration occur?

a)

Cytoplasm and mitochondria

b)

Nucleus and chloroplast

c)

Cell wall and cytoplasm

d)

Vacuole and ribosome

19.

Explain the process of chemical reactions such as photosynthesis and/or cellular respiration. What is the name of the organelle where most energy (ATP) is produced during cellular respiration?

a)

Chloroplast

b)

Mitochondrion

c)

Cytoplasm

d)

Ribosome

20.

Explain the process of chemical reactions such as photosynthesis and/or cellular respiration. In which type of cells does cellular respiration occur?

a)

Only in plant cells

b)

Only in animal cells

c)

In both plant and animal cells

d)

Only in green cells

21.

Explain the process of chemical reactions such as photosynthesis and/or cellular respiration. During which process does energy get stored in glucose molecules?

a)

Photosynthesis

b)

Cellular respiration

c)

Germination

d)

Transpiration

22.

Explain the process of chemical reactions such as photosynthesis and/or cellular respiration. During which process does energy get released from glucose molecules?

a)

Photosynthesis

b)

Cellular respiration

c)

Transpiration

d)

Germination

23.

Explain the process of chemical reactions such as photosynthesis and/or cellular respiration. Where does the first step of cellular respiration (glycolysis) occur?

a)

In the cytoplasm

b)

In the mitochondria

c)

In the nucleus

d)

In the chloroplast

24.

Explain the process of chemical reactions such as photosynthesis and/or cellular respiration. What happens during the first step of cellular respiration?

a)

Oxygen combines with glucose to form water

b)

Glucose is broken down into smaller molecules and a little ATP is released

c)

Carbon dioxide is absorbed

d)

Energy is stored as sugar

25.

Explain the process of chemical reactions such as photosynthesis and/or cellular respiration. Where does the second step of cellular respiration occur?

a)

Cytoplasm

b)

Mitochondria

c)

Chloroplast

d)

Nucleus

26.

Explain the process of chemical reactions such as photosynthesis and/or cellular respiration. What happens during the second step of cellular respiration?

a)

The smaller molecules from glycolysis react with oxygen to produce water, carbon dioxide, and large amounts of ATP

b)

Glucose is split into smaller parts

c)

Light energy is absorbed

d)

The plant stores glucose

27.

Explain the process of chemical reactions such as photosynthesis and/or cellular respiration. What is produced at the end of the second step of cellular respiration?

a)

Glucose and oxygen

b)

Carbon dioxide, water, and large amounts of ATP

c)

Light energy and sugar

d)

Hydrogen and water

28.

List the organisms that are photosynthetic. List the organisms that perform cellular respiration. Which organisms can perform photosynthesis?

a)

Fungi and bacteria

b)

Only plants

c)

Plants, algae, and some bacteria

d)

Only plants

29.

List the organisms that are photosynthetic. List the organisms that perform cellular respiration. Which cell structure allows photosynthetic organisms to capture sunlight?

a)

Mitochondria

b)

Nucleus

c)

Chloroplast

d)

Vacuole

30.

List the organisms that are photosynthetic. List the organisms that perform cellular respiration. Which organisms perform cellular respiration?

a)

Only animals

b)

Only plants

c)

All living organisms

d)

Only green algae

31.

List the organisms that are photosynthetic. List the organisms that perform cellular respiration. What is the main purpose of cellular respiration in organisms?

a)

To make oxygen

b)

To release energy from food

c)

To absorb sunlight

d)

To make carbon dioxide

32.

What is the main purpose of photosynthesis?

a)

To release energy from food

b)

To make food using sunlight

c)

To produce ATP directly

d)

To break down glucose

33.

Which of the following organisms perform both photosynthesis and cellular respiration?

a)

Humans

b)

Green plants

c)

Mushrooms

d)

Insects

34.

Which of the following organisms perform only cellular respiration but not photosynthesis?

a)

Green plants

b)

Cyanobacteria

c)

Fungi

d)

Algae

35.

Which organelle is responsible for energy release during cellular respiration?

a)

Chloroplast

b)

Mitochondrion

c)

Ribosome

d)

Vacuole

36.

Which group of microorganisms can photosynthesize like plants?

a)

Protozoa

b)

Cyanobacteria

c)

Yeasts

d)

Molds

37.

In which part of the plant does photosynthesis mostly occur?

a)

Roots

b)

Stems

c)

Leaves

d)

Flowers

38.

Classify producers, consumers, and detritivores by their source of energy and explain the relationship between consumers, producers, and detritivores in an ecosystem.

a)

Producers produce energy mainly by cellular respiration; consumers absorb sunlight; detritivores eat living predators.

b)

Producers use sunlight to make food; consumers obtain energy by eating other organisms; detritivores feed on dead matter and recycle nutrients back to producers.

c)

Producers get energy by eating consumers; consumers carry out photosynthesis; detritivores stop nutrient cycling.

d)

Producers and consumers both recycle nutrients; detritivores create energy for the ecosystem.

39.

Define herbivore, carnivore, omnivore.

a)

Herbivore eats plants; carnivore eats animals; omnivore eats both plants and animals.

b)

Herbivore eats animals; carnivore eats plants; omnivore eats only plants.

c)

Herbivore eats fungi; carnivore eats plants and animals; omnivore eats detritus.

d)

Herbivore eats decomposers; carnivore eats plants; omnivore eats only animals.

40.

What are the differences between a food chain, a food web, and a food pyramid?

a)

Food chain shows interconnected feeding relationships; food web is a single path; food pyramid shows organisms only by size.

b)

Food chain is a linear path of energy transfer; food web shows many interconnected chains; food pyramid represents energy decreasing at higher trophic levels.

c)

Food chain shows energy amounts at each level; food web shows only producers; food pyramid is a list of consumers.

d)

Food chain is circular; food web is random; food pyramid shows only numbers of organisms.

41.

Nonliving parts that supply materials for producers are ______.

a)

air, water, and soil

b)

leaves and roots

c)

animals and fungi

d)

energy pyramids

42.

In what direction does energy flow in an ecosystem?

a)

From consumers → producers

b)

From producers → consumers

c)

Back and forth

d)

Randomly

43.

Which statement about energy flow is correct?

a)

Energy is recycled.

b)

Energy flows in one direction only.

c)

Energy increases at each level.

d)

Energy stays constant.

44.

What role do decomposers play in the flow of energy?

a)

They create energy.

b)

They recycle nutrients to producers.

c)

They stop energy loss.

d)

They reflect sunlight.

45.

Which of the following is a biotic part of an ecosystem?

a)

Temperature

b)

Fungi

c)

Rocks

d)

Water

46.

Which of the following is abiotic?

a)

Bacteria

b)

Sunlight

c)

Plants

d)

Worms

47.

How is energy lost at each trophic level?

a)

Through heat during life processes

b)

It disappears completely

c)

It doubles at each level

d)

It is recycled by decomposers

48.

Which organism transfers solar energy into chemical energy?

a)

Rabbit

b)

Tree

c)

Hawk

d)

Mushroom

49.

What percent of energy passes to the next trophic level?

a)

100 %

b)

50 %

c)

10 %

d)

1 %

50.

In an energy pyramid, which level has the least available energy?

a)

Producers

b)

Primary consumers

c)

Secondary consumers

d)

Top predators

51.

The arrows in a food web represent ______.

a)

Matter flow

b)

Energy flow

c)

Direction of light

d)

Amount of heat

52.

When decomposers break down dead organisms, the nutrients ______.

a)

leave the ecosystem forever

b)

are released into soil, air, or water

c)

turn into energy

d)

disappear

53.

Why can energy not be recycled in an ecosystem?

a)

It changes to heat and escapes to the environment.

b)

Decomposers trap it permanently.

c)

Producers store it forever.

d)

It becomes matter.

54.

Which of the following best shows the correct energy path?

a)

Decomposer → Producer → Consumer

b)

Sun → Producer → Consumer → Decomposer

c)

Consumer → Producer → Sun

d)

Producer → Decomposer → Consumer

55.

What happens to energy that is not transferred to the next trophic level?

a)

It becomes part of the soil.

b)

It is lost as heat to the surroundings.

c)

It becomes recycled.

d)

It returns to the Sun.

56.

Which group of organisms changes sunlight into usable chemical energy?

a)

Herbivores

b)

Omnivores

c)

Autotrophs

d)

Decomposers

57.

Why are decomposers important for producers?

a)

They make oxygen.

b)

They return nutrients to the soil that plants need.

c)

They block sunlight to save energy.

d)

They store food for other animals.

58.

In a desert ecosystem, which of these is a nonliving factor affecting energy flow?

a)

Cactus

b)

Lizard

c)

Heat

d)

Scorpion

59.

Which statement about matter and energy is true?

a)

Both energy and matter cycle.

b)

Energy flows in one direction; matter cycles.

c)

Matter flows in one direction; energy cycles.

d)

Both are destroyed in each process.

60.

If the number of decomposers decreases, what will happen?

a)

Nutrients will build up in dead matter.

b)

Energy flow will increase.

c)

More sunlight will be absorbed.

d)

Oxygen will stop being produced.

61.

Which of these animals is both a primary and a secondary consumer?

a)

Rabbit

b)

Frog

c)

Hawk

d)

Human

62.

What would most likely happen if all producers disappeared from an ecosystem?

a)

Consumers would increase.

b)

The entire food web would collapse.

c)

Decomposers would replace them.

d)

Producers would replace them.

63.

What connects producers, consumers, and decomposers together?

a)

Flow of heat energy

b)

Flow of nutrients and energy

c)

Flow of water only

d)

Flow of light only

64.

Analyze the food web. Which statement is correct? The diagram shows the Sun, leaves, fruit, dead fruit, fungus, ants, butterfly, beetle, sloth, squirrel monkey, harpy eagle, and scarlet macaw connected by arrows indicating who eats whom.

a)

The model tracks the transfer of energy as energy flows in this ecosystem.

b)

The transfer of matter back into the environment occurs only at the detritivore level.

c)

The model shows the transfer of heat energy only.

d)

Decomposers in the model use matter but not energy as they recycle matter back into life processes.

65.

In an energy pyramid, about 10% of the energy available at one trophic level is passed to the next level. Which statement best explains why this happens?

a)

Consumers eat both producers and other consumers.

b)

Organisms use most of the available energy to fuel their own life processes.

c)

Predators eat more organisms in their own level than in other levels.

d)

Producers exist only in the lowest level of the pyramid.

66.

Which organism is a producer in an ecosystem?

a)

Lion

b)

Grass

c)

Snake

d)

Frog

67.

What do producers use as their main source of energy?

a)

Other animals

b)

Sunlight

c)

Soil

d)

Oxygen

68.

Which statement best describes a consumer?

a)

It makes its own food.

b)

It breaks down dead matter.

c)

It eats other organisms to get energy.

d)

It absorbs sunlight to grow.

69.

Detritivores get their energy by:

a)

Eating living plants

b)

Breaking down dead plants and animals

c)

Making food from sunlight

d)

Hunting for prey

70.

How are producers, consumers, and detritivores connected?

a)

They all make their own food.

b)

They recycle energy and nutrients in an ecosystem.

c)

They only live in oceans.

71.

What is a herbivore?

a)

An animal that eats only meat

b)

An animal that eats only plants

c)

An animal that eats both plants and animals

d)

An organism that breaks down waste

72.

Which of the following is a carnivore?

a)

Cow

b)

Rabbit

c)

Lion

d)

Deer

73.

Humans are examples of:

a)

Herbivores

b)

Carnivores

c)

Omnivores

d)

Producers

74.

Which of the following shows energy flow in the correct order?

a)

Consumer → Producer → Sun

b)

Sun → Producer → Consumer → Detritivore

c)

Detritivore → Consumer → Producer

d)

Producer → Sun → Consumer

75.

Which statement about a food chain is correct?

a)

It shows one single path of energy flow.

b)

It shows all feeding relationships in an ecosystem.

c)

It shows how nutrients recycle in the soil.

d)

It shows the number of organisms in each level.

76.

How is a food web different from a food chain?

a)

It includes many food chains linked together.

b)

It only includes producers.

c)

It has no arrows to show energy flow.

d)

It starts with a carnivore.

77.

What does a food pyramid show?

a)

The number of predators in each level

b)

How energy decreases at each feeding level

c)

The amount of water in an ecosystem

d)

The temperature in a biome

78.

In an energy pyramid, approximately 10 percent of the energy available in one trophic level is transferred to the next level. Which statement helps explain why this occurs?

a)

Consumers eat both producers and other consumers.

b)

Organisms use most of the available energy to fuel their own life processes.

c)

Predators eat more organisms in their own level than organisms in other levels.

d)

Producers exist in only the lowest level of the pyramid.

79.

Describe the following cycles of matter: Which statement best describes the nitrogen cycle in Earth systems?

a)

Nitrogen is created by plants and remains only in living tissues

b)

Nitrogen continuously moves between the atmosphere, soil, and living things through processes such as fixation, uptake by plants, decomposition, and denitrification

c)

Nitrogen exists only as nitrogen gas in the atmosphere and does not enter organisms

d)

Nitrogen is stored underground and never returns to the atmosphere

80.

Describe the following cycles of matter: Which statement best describes the carbon cycle in Earth systems?

a)

Carbon moves in one direction only from plants to animals

b)

Carbon cycles among the atmosphere, oceans, and living things through processes such as photosynthesis, respiration, decomposition, and combustion

c)

Carbon is created only by animals and remains in the atmosphere

d)

Carbon changes into nitrogen as it moves through organisms

81.

Describe the following cycles of matter: Which statement best describes the water cycle in Earth systems?

a)

Water stays only in oceans and lakes

b)

Water continuously circulates through evaporation, condensation, precipitation, and collection across Earth

c)

Water moves only upward into clouds and does not return to the surface

d)

Water changes into carbon during photosynthesis

82.

Describe the following cycles of matter: Which statement best describes the oxygen cycle in Earth systems?

a)

Oxygen is produced only by animals and stored underground

b)

Oxygen cycles between the atmosphere and living things as photosynthesis releases oxygen and respiration uses oxygen

c)

Oxygen moves in one direction from plants to soil and never returns to air

d)

Oxygen exists only as ozone and does not enter organisms

83.

What is nitrogen fixation? Keisha and her classmates created a model of the nitrogen cycle. Their diagram is shown below. Based on the model, what is nitrogen fixation?

a)

Storing nitrogen underground

b)

Changing nitrogen gas into usable nitrogen compounds in the soil

c)

Removing nitrogen from air

d)

Adding oxygen to nitrogen

84.

What does the Law of Conservation of Mass state?

a)

Matter can be created but not destroyed

b)

Matter changes form but is neither created nor destroyed

c)

Matter disappears after a chemical reaction

d)

Matter is always solid

85.

Matter and nutrients move through the environment in:

a)

Straight lines

b)

One direction

c)

Cycles

d)

Chains

86.

What is the main idea of the Carbon Cycle?

a)

Carbon moves in one direction only

b)

Carbon cycles between living organisms and the atmosphere

c)

Carbon is created by plants

d)

Carbon comes only from animals

87.

During photosynthesis, plants use carbon dioxide to produce:

a)

Oxygen and glucose

b)

Water vapor

c)

Nitrogen

d)

Proteins

88.

Which process returns carbon dioxide back into the atmosphere?

a)

Photosynthesis

b)

Respiration

c)

Transpiration

d)

Nitrogen fixation

89.

In the Water Cycle, which process changes liquid water to vapor (gas)?

a)

Condensation

b)

Evaporation

c)

Precipitation

d)

Collection

90.

What process releases water vapor from plant leaves?

a)

Transpiration

b)

Evaporation

c)

Condensation

d)

Precipitation

91.

What is precipitation?

a)

Rain, snow, sleet, or hail falling from clouds

b)

Water changing to gas

c)

Clouds forming

d)

Plants absorbing sunlight

92.

In the Nitrogen Cycle, plants and animals cannot use nitrogen gas (N₂) directly because:

a)

It is too heavy

b)

It must first be changed into nitrogen compounds

c)

It reacts with oxygen

d)

It only dissolves in water

93.

What is nitrogen fixation?

a)

Storing nitrogen underground

b)

Changing nitrogen gas into usable nitrogen compounds in the soil

c)

Removing nitrogen from air

d)

Adding oxygen to nitrogen

94.

Which of the following can perform nitrogen fixation?

a)

Fungi only

b)

Root bacteria, lightning, and rain

c)

Humans and animals

d)

Oxygen from plants

95.

In the Oxygen Cycle, photosynthesis and respiration are:

a)

Opposite and balanced processes

b)

Unrelated processes

c)

The same process

d)

Done only by animals

96.

During respiration, organisms release:

a)

Oxygen only

b)

Carbon dioxide and energy

c)

Nitrogen gas

d)

Water vapor only

97.

What adds oxygen to the atmosphere?

a)

Photosynthesis

b)

Respiration

c)

Evaporation

d)

Nitrogen fixation

98.

What do decomposers do in all matter cycles?

a)

Destroy matter

b)

Return nutrients to the soil

c)

Produce oxygen

d)

Prevent recycling

99.

What is the function of the bacteria shown in the model?

a)

They prevent the nitrogen from harming the plants

b)

They remove the nitrogen from the soil

c)

They remove the oxygen from the soil

d)

They return the nitrogen to the system

100.

Which of the following statements is NOT true about systems that cycle matter?

a)

Living things play a role in the cycling of matter

b)

Matter changes form as it cycles

c)

Some matter is destroyed as it cycles through the environment

d)

Matter is constantly cycling through the environment

101.

Describe nitrogen cycle: Choose the statement that best summarizes the nitrogen cycle.

a)

Nitrogen remains only as a gas and is not used by organisms

b)

Nitrogen moves among the atmosphere, soil, and organisms through fixation, assimilation, decomposition, and denitrification

c)

Nitrogen is produced solely by animals and stored in oceans

d)

Nitrogen changes into carbon during photosynthesis

102.

Describe water cycle: Choose the statement that best summarizes the water cycle.

a)

Water stays only in lakes and does not move

b)

Water circulates through evaporation, condensation, precipitation, and collection across Earth

c)

Water turns into oxygen in plants

d)

Water travels only underground

103.

Describe carbon cycle: Choose the statement that best summarizes the carbon cycle.

a)

Carbon is created only by plants and remains in forests

b)

Carbon cycles among atmosphere, oceans, and living things via photosynthesis, respiration, decomposition, and combustion

c)

Carbon does not enter the atmosphere

d)

Carbon changes into nitrogen in animals

104.

List reasons why populations would decrease: Which factor most directly causes a population to decrease?

a)

High birth rate and abundant resources

b)

Disease outbreak reducing survival

c)

Immigration into the population

d)

Expansion of suitable habitat

105.

List reasons why populations increase: Which factor most directly causes a population to increase?

a)

Severe drought reducing food

b)

Predation pressure rising

c)

Abundant resources leading to higher birth rates

d)

Widespread disease

106.

Define extinct. What characterizes extinction?

a)

A species has very low numbers but still survives in some locations

b)

A species is found only in zoos

c)

No individuals of the species remain alive anywhere on Earth

d)

A species migrates to a new habitat

107.

Which of the following is an abiotic factor in an ecosystem?

a)

Tree

b)

Frog

c)

Water

d)

Mushroom

108.

Which of the following best describes a limiting factor?

a)

Anything that increases a population without limit

b)

Anything that stops or reduces how big a population can grow

c)

The total number of organisms in an area

d)

The largest amount of food available

109.

Which of these is a biotic factor that affects population size?

a)

Amount of rainfall

b)

Soil pH

c)

Predation and competition

d)

Temperature

110.

What is the carrying capacity of an ecosystem?

a)

The maximum number of organisms that can live in an ecosystem over time

b)

The total amount of water available

c)

The smallest possible population size

d)

The number of predators in an ecosystem

111.

What is meant by biotic potential?

a)

The maximum growth possible if conditions are perfect

b)

The number of animals living in one area

c)

The limit beyond which a population cannot grow

d)

The total amount of energy in an ecosystem

112.

Which factor would most likely cause a population to decrease?

a)

Plentiful food and water

b)

Mild temperature

c)

Drought and lack of resources

d)

Increased space

113.

A drought decreases the amount of grass in a prairie ecosystem. Which population would be most directly affected?

a)

Predators that eat deer

b)

Deer that eat grass

c)

Birds that build nests in trees

d)

Frogs that live in ponds

114.

When a population becomes too large for the available resources, it is called:

a)

Carrying capacity

b)

Overpopulation

c)

Extinction

d)

Biotic potential

115.

Which of the following could cause overpopulation?

a)

Fewer predators

b)

Limited food

c)

Drought

d)

Natural disasters

116.

Which of these events would most likely cause a sudden population decrease?

a)

Plenty of sunlight

b)

Introduction of a new predator

c)

Increase in space

d)

Stable temperature

117.

What is the difference between endangered and threatened species?

a)

Endangered species are closer to extinction than threatened species.

b)

Threatened species are already extinct.

c)

Threatened species are completely safe from extinction.

d)

Both mean the same thing.

118.

Which of these would cause a species to become extinct?

a)

Overpopulation of prey

b)

Loss of habitat and pollution

c)

Increased reproduction rates

d)

Balanced resources

119.

What is the main reason populations increase?

a)

More predators

b)

Availability of resources and favorable conditions

c)

Lack of space

d)

Spread of disease

120.

Which graph pattern shows that a population has reached its carrying capacity?

a)

A line that keeps rising without stopping

b)

A line that rises then levels off

c)

A line that drops to zero

d)

A flat horizontal line at the bottom

121.

When the number of individuals in a population exceeds its carrying capacity, what will most likely happen?

a)

The population will remain the same.

b)

The population will decrease due to lack of resources.

c)

The population will grow faster.

d)

The ecosystem will expand to fit more organisms.

122.

Which is an example of a physical change in an ecosystem that affects population?

a)

Drought or flood

b)

New predator

c)

Disease spread

d)

Competition

123.

Which is an example of a biological change that affects population size?

a)

Volcanic eruption

b)

Earthquake

c)

Increase in predators or disease

d)

Flood

124.

What is a limiting factor that humans often affect?

a)

Sunlight

b)

Temperature

c)

Space and resources through urban growth

d)

Soil type

125.

Why can overpopulation harm an environment?

a)

It increases available resources.

b)

It causes competition and resource shortage.

c)

It reduces biodiversity.

d)

Both b and c.

126.

Which statement best describes how populations and resources are connected?

a)

When resources increase, populations usually decrease.

b)

When resources decrease, populations increase.

c)

When resources decrease, populations also decrease.

d)

Populations and resources are unrelated.

127.

Study the graph of a coyote population in a habitat with plentiful food and no predators. Interpret what is happening to the population size at the one-year mark.

a)

The population size is increasing.

b)

The population size is decreasing.

c)

The population size is remaining the same.

d)

The population size cannot be inferred from the graph.

128.

Which statement best explains what happened to the coyote population size when it reached its carrying capacity, and why?

a)

The population size continued to increase because the ecosystem had not changed.

b)

The population size stopped increasing because it had reached the largest number of coyotes the ecosystem could support.

c)

The population size became zero because the ecosystem could no longer support the coyotes.

d)

The population size can no longer be inferred from the graph once carrying capacity is reached.

129.

What is a symbiotic relationship?

a)

A relationship where one organism hunts another for food

b)

A close and long-term interaction between organisms of different species

c)

A competition between animals for sunlight and water

d)

A short-term feeding interaction

130.

In mutualism, both organisms:

a)

Compete for the same resource

b)

Benefit from the relationship

c)

Harm each other

d)

Remain unaffected

131.

In parasitism, the organism that benefits is called the:

a)

Prey

b)

Host

c)

Parasite

d)

Predator

132.

Which example shows commensalism?

a)

A tick feeding on a dog

b)

A clownfish and sea anemone

c)

A bird building its nest in a tree without harming it

d)

A wolf and a crow sharing a kill

133.

Which relationship benefits one organism but harms the other?

a)

Mutualism

b)

Parasitism

c)

Commensalism

d)

Cooperation

134.

Which of the following is an example of mutualism?

a)

A flea living on a dog

b)

Bees pollinating flowers

c)

A lion hunting a zebra

d)

Moss growing on a rock

135.

Which statement best describes a predator-prey relationship?

a)

Two species share food equally

b)

One organism hunts and eats another

c)

Both organisms benefit equally

d)

One organism lives inside another

136.

What is a competitive relationship?

a)

When two or more organisms fight or struggle for the same resource

b)

When two species live peacefully together

c)

When one animal hunts another

d)

When animals share food

137.

Which is a correct example of competition?

a)

Wolves and crows feeding on the same carcass

b)

Bees and flowers exchanging nectar for pollination

c)

A bird removing ticks from a buffalo

d)

A snake eating a frog

138.

Which describes a cooperative relationship?

a)

Elephants working together to protect their young

b)

Lions and zebras in a food chain

c)

Trees competing for sunlight

d)

A parasite feeding on a host

139.

Which of the following is an example of a predator-prey relationship?

a)

Leaf-cutter ants carrying leaves together

b)

An osprey catching a fish

c)

A bird building a nest in a tree

d)

A clownfish and sea anemone

140.

In a competitive relationship:

a)

Both species are helped

b)

Both species are harmed

c)

Organisms struggle for limited resources

d)

One benefits and one is unaffected

141.

Which type of relationship exists between leaf-cutter ants that build homes together?

a)

Cooperative

b)

Mutualistic

c)

Parasitic

d)

Competitive

142.

Which statement about commensalism is correct?

a)

Both species benefit

b)

One species benefits, the other is unaffected

c)

One species benefits, the other is harmed

d)

Both are harmed

143.

Which relationship describes a wasp laying eggs inside a spider?

a)

Parasitism

b)

Mutualism

c)

Competition

d)

Cooperation

144.

Which type of relationship helps both partners survive?

a)

Parasitism

b)

Competition

c)

Mutualism

d)

Commensalism

145.

Which type of relationship is shown when squirrels work together to find food safely?

a)

Cooperative

b)

Competitive

c)

Parasitic

d)

Predator-prey

146.

What is the host in a parasitic relationship?

a)

The organism that benefits

b)

The organism that is harmed

c)

The organism that competes

d)

The organism that hunts

147.

Which example best shows a competitive relationship among plants?

a)

Trees growing tall to reach sunlight

b)

Birds cleaning crocodile teeth

c)

Bees travelling to reach sunlight

d)

Birds cleaning crocodile teeth again

148.

Which term refers to organisms living in the same area and interacting as a group?

a)

Population

b)

Community

149.

Which of the following occurs during secondary succession?

a)

Life starts for the first time on bare rock.

b)

Soil has to form from lava rock.

c)

Plants regrow after a forest fire or flood.

d)

There are no nutrients or water available.

150.

After a forest fire, small plants start to grow again. What kind of change is this?

a)

Primary succession

b)

Secondary succession

c)

Climax community

d)

Aquatic succession