Ecosystem Ecology: Interactions, Energy Flow, and Stability

Question 1

Identify the process that suggests an ecosystem is experiencing stress:

Accepted Answer

Dominance of a limited number of species

Answer

Elevated species diversity

Answer

Enhanced nutrient cycling

Answer

Balanced interactions between predators and prey

Question 2

In an ecosystem, identify the three main trophic levels and explain the unidirectional flow of energy among them. Specify the approximate percentage of energy transferred between levels.

Accepted Answer

Producers, consumers, decomposers; energy flows one way, with about 10% transferred to each higher level.

Answer

Producers, decomposers, consumers; energy flows in a complex network, with varying transfer rates.

Answer

Consumers, producers, decomposers; energy flows both ways, with losses at each transfer.

Answer

Decomposers, producers, consumers; energy is stored at each level and released during decomposition.

Question 3

Ecosystem stability refers to the ability of an ecosystem to maintain its structure and function in the face of disturbances. Which of the following is NOT a characteristic of a stable ecosystem?

Accepted Answer

A few dominant species controlling the community structure

Answer

High species diversity within each trophic level

Answer

Rapid nutrient cycling promoting primary productivity

Answer

Strong negative feedback mechanisms regulating ecosystem processes

Question 4

Which principle is NOT a guiding concept in conservation and restoration ecology?

Accepted Answer

Focus exclusively on protecting individual species

Answer

Prioritize habitat connectivity

Answer

Restore degraded ecosystems

Answer

Minimize habitat fragmentation

Question 5

Which of the following is **not** considered a fundamental component of an ecosystem?

Accepted Answer

Exchange of currency

Answer

Living organisms (biotic factors)

Answer

Non-living factors (abiotic factors)

Answer

Nutrient exchange

Question 6

The term 'nutrient cycling' describes the process by which:

Accepted Answer

Nutrients are continuously recycled within an ecosystem

Answer

Photosynthesis occurs in plants

Answer

Organisms release waste into the environment

Answer

Water evaporates from bodies of water

Question 7

Which of the following is an example of a keystone species that plays a crucial role in maintaining ecosystem balance?

Accepted Answer

Sea otter

Answer

Shark

Answer

Blue whale

Answer

Cheetah

Question 8

The term 'biome' refers to:

Accepted Answer

A specific type of ecosystem characterized by its climate and vegetation

Answer

A group of organisms that share a habitat

Answer

The total amount of living matter in an ecosystem

Answer

The rate at which energy flows through an ecosystem

Question 9

Which of the following characteristics **does not** indicate a healthy and functioning ecosystem?

Accepted Answer

Low productivity

Answer

High biodiversity

Answer

Resilience to disturbances

Answer

Balanced nutrient cycling

Question 10

The process by which plants use sunlight to convert carbon dioxide and water into energy-rich molecules is known as:

Accepted Answer

Photosynthesis

Answer

Respiration

Answer

Chemosynthesis

Answer

Transpiration

Question 11

The 'carrying capacity' of an ecosystem refers to:

Accepted Answer

The maximum population size that an ecosystem can sustainably support

Answer

The rate at which a population increases

Answer

The number of individuals that can be added to a population without causing a decline

Answer

The population density at which resources become scarce

Question 12

What is the term for the movement of energy through an ecosystem?

Accepted Answer

Energy flow

Answer

Nutrient cycling

Answer

Decomposers

Answer

Biosphere

Question 13

What does the trophic level of an organism refer to?

Accepted Answer

Its position within the food chain

Answer

Its nutritional status

Answer

Its size and shape

Answer

Its age and life stage

Question 14

What is the field of study that examines interactions between organisms and their surroundings called?

Accepted Answer

Ecology

Answer

Biology

Answer

Environmental science

Answer

Geology

Question 15

Which of the following is NOT a component of an ecosystem?

Accepted Answer

Social factors

Answer

Biotic factors

Answer

Abiotic factors

Answer

Community interactions

Question 16

The process by which energy flows through an ecosystem is known as:

Accepted Answer

Food chain

Answer

Carbon cycle

Answer

Nitrogen cycle

Answer

Water cycle

Question 17

The concept of ecological niche refers to:

Accepted Answer

The role an organism plays in its environment

Answer

The physical habitat an organism occupies

Answer

The range of environmental conditions an organism can tolerate

Answer

The interactions between organisms in a community

Question 18

The process by which nitrogen is converted into forms usable by plants is called:

Accepted Answer

Nitrogen fixation

Answer

Nitrification

Answer

Denitrification

Answer

Assimilation

Question 19

Which of the following is a characteristic of a sustainable ecosystem?

Accepted Answer

High resilience

Answer

Low biodiversity

Answer

Depletion of resources

Answer

Pollution buildup

Question 20

The term 'symbiosis' refers to:

Accepted Answer

Interactions between organisms

Answer

Ecological niches

Answer

Ecosystem resilience

Answer

Energy flow

Question 21

The study of interactions between organisms and their environment is known as:

Accepted Answer

Ecology

Answer

Biology

Answer

Physics

Answer

Chemistry

Question 22

Primary producers in an ecosystem are responsible for:

Accepted Answer

Converting solar energy into chemical energy

Answer

Decomposing organic matter

Answer

Consuming other organisms for energy

Answer

Regulating nutrient cycling

Question 23

The process by which nutrients are recycled within an ecosystem is known as:

Accepted Answer

Decomposition

Answer

Nitrification

Answer

Denitrification

Answer

Fixation

Question 24

Which of the following is a keystone species?

Accepted Answer

A species that has a disproportionately large impact on its ecosystem relative to its abundance

Answer

A species that is at the bottom of the food chain

Answer

A species that is found in all ecosystems

Answer

A species that is a primary producer

Question 25

Which biome is characterized by a lack of trees, extreme temperatures, and sparse vegetation?

Accepted Answer

Tundra

Answer

Temperate forest

Answer

Tropical rainforest

Answer

Grassland

Question 26

The measurement of the total amount of energy produced by organisms in an ecosystem is known as:

Accepted Answer

Gross primary productivity

Answer

Net primary productivity

Answer

Secondary productivity

Answer

Community respiration

Question 27

Which of the following is a non-renewable resource in an ecosystem?

Accepted Answer

Fossil fuels

Answer

Water

Answer

Solar energy

Answer

Biomass

Question 28

The process by which energy flows through an ecosystem is termed:

Accepted Answer

Energy transfer

Answer

Primary production

Answer

Secondary production

Answer

Nutrient cycling

Question 29

Which of the following factors does NOT affect the rate of nutrient cycling in an ecosystem?

Accepted Answer

Altitude

Answer

Temperature

Answer

pH

Answer

Decomposition rate

Question 30

A food web depicts:

Accepted Answer

All feeding relationships within an ecosystem

Answer

All organisms within an ecosystem

Answer

All producers within an ecosystem

Answer

All consumers within an ecosystem

Question 31

Which of the following is an example of a primary producer?

Accepted Answer

Grass

Answer

Deer

Answer

Wolf

Answer

Bacteria

Question 32

The term 'trophic level' refers to:

Accepted Answer

The position of an organism within a food web

Answer

The amount of energy consumed by an organism

Answer

The function of an organism in an ecosystem

Answer

The size of an organism

Question 33

The concept of 'carrying capacity' refers to:

Accepted Answer

The maximum population size sustainable within a given environment

Answer

The rate of population growth

Answer

The equilibrium population size

Answer

The availability of resources in an environment

Question 34

Which of the following is NOT a human impact on ecosystems?

Accepted Answer

Volcanic eruptions

Answer

Deforestation

Answer

Climate change

Answer

Overpopulation

Question 35

The study of interactions between organisms and their environment is referred to as:

Accepted Answer

Ecology

Answer

Biology

Answer

Chemistry

Answer

Physics

Question 36

How do microbes contribute to nutrient cycling in an ecosystem, and how do their activities affect nutrient availability?

Accepted Answer

Microbes break down dead organisms and organic matter, releasing nutrients back into the environment.

Answer

Plants and algae are responsible for nutrient cycling through photosynthesis.

Answer

Animals obtain nutrients by consuming other organisms, contributing to nutrient cycling.

Answer

Top predators indirectly influence nutrient cycling by controlling populations of other organisms.

Question 37

In a typical ecosystem, which trophic level possesses the highest total biomass?

Accepted Answer

Producers (plants)

Answer

Primary consumers (herbivores)

Answer

Secondary consumers (carnivores)

Answer

Tertiary consumers (top predators)

Question 38

Which process is primarily responsible for converting light energy into chemical energy in plant organisms?

Accepted Answer

Photosynthesis

Answer

Cellular respiration

Answer

Chemosynthesis

Answer

Transpiration

Question 39

Within an ecosystem, what is the primary function of decomposers?

Accepted Answer

Decomposing organic matter and recycling nutrients

Answer

Producing oxygen through photosynthesis

Answer

Fixing nitrogen from the atmosphere

Answer

Preying upon and consuming herbivores

Question 40

What term refers to the variety of different species that coexist within a particular ecosystem?

Accepted Answer

Biodiversity

Answer

Biogeography

Answer

Ecology

Answer

Phenology

Question 41

Which term describes the specific role and requirements of a particular species within its ecosystem?

Accepted Answer

Ecological niche

Answer

Symbiosis

Answer

Interspecific competition

Answer

Mutualism

Question 42

What is the primary source of energy that sustains most ecosystems on Earth?

Accepted Answer

Solar energy

Answer

Nuclear energy

Answer

Fossil fuels

Answer

Electrical energy

Question 43

Which of the following is NOT a primary factor in determining the distribution and characteristics of Earth's biomes?

Accepted Answer

Human population density

Answer

Climatic conditions

Answer

Soil properties

Answer

Geographic features

Question 44

The process by which plants use sunlight, water, and carbon dioxide to produce glucose and release oxygen is called:

Accepted Answer

Photosynthesis

Answer

Chemosynthesis

Answer

Respiration

Answer

Aerobic respiration

Question 45

In an ecosystem, an organism that exerts a disproportionately large effect on its community relative to its abundance is referred to as a:

Accepted Answer

Keystone species

Answer

Pioneer species

Answer

Dominant species

Question 46

The process through which bacteria and fungi break down organic matter into simpler compounds, releasing nutrients back into the environment, is known as:

Accepted Answer

Decomposition

Answer

Nitrification

Answer

Mineralization

Answer

Humification

Question 47

Which of the following human activities is a major contributor to the greenhouse effect and climate change?

Accepted Answer

Burning fossil fuels

Answer

Promoting sustainable agriculture

Answer

Investing in renewable energy

Answer

Protecting forests

Question 48

The term 'ecological succession' describes:

Accepted Answer

The predictable and gradual change in plant communities over time in a given area

Answer

The impact of invasive species on native ecosystems

Answer

The sudden and unpredictable change in species composition

Answer

The seasonal variation in plant diversity

Question 49

A mutually beneficial relationship between two species is known as:

Accepted Answer

Mutualism

Answer

Competition

Answer

Commensalism

Answer

Parasitism

Question 50

The concept of 'ecological footprint' measures:

Accepted Answer

The amount of land and water required to sustain a human population and absorb its waste

Answer

The rate at which biodiversity is declining

Answer

The number of endangered species in an ecosystem