CYCLES

Question 1

What are the steps of the nitrogen cycle?

Answer 1

Fixation → Nitrification → Assimilation → Ammonification → Denitrification

Question 2

What is nitrogen fixation?

Answer 2

The process where bacteria convert nitrogen gas (N2) from the atmosphere into ammonium (NH4+)

Question 3

What is nitrification?

Answer 3

The process where bacteria convert ammonium (NH4+) into nitrates (NO3-)

Question 4

What is assimilation in the nitrogen cycle?

Answer 4

The process where plants absorb nitrates from the soil to use for growth

Question 5

What is ammonification?

Answer 5

The process where decomposers break down dead organisms and waste to release ammonium (NH4+)

Question 6

What is denitrification?

Answer 6

The process where bacteria convert nitrates back into nitrogen gas (N2)

Question 7

Why is nitrogen essential?

Answer 7

It is needed to build amino acids and nucleic acids in living organisms

Question 8

Why can’t organisms use nitrogen gas (N2) directly from the air?

Answer 8

Because it is inert and must be converted into usable forms like nitrate or ammonium

Question 9

How is nitrogen made usable for organisms?

Answer 9

Through bacterial processes like fixation and nitrification

Question 10

What are the usable forms of nitrogen for plants?

Answer 10

Nitrates (NO3-)

Question 11

What are the main processes of the water cycle?

Answer 11

Evaporation

Question 12

What is evaporation?

Answer 12

The process where liquid water turns into vapor and rises into the air

Question 13

What is condensation?

Answer 13

The process where water vapor cools and turns into clouds

Question 14

What is precipitation?

Answer 14

Water that falls from the sky as rain

Question 15

What is collection or runoff?

Answer 15

The gathering of water in oceans

Question 16

What does the phosphorus cycle help produce?

Answer 16

ATP

Question 17

Where is phosphorus found?

Answer 17

In rocks and soil

Question 18

How does phosphorus enter the soil?

Answer 18

Through the weathering of rocks by water

Question 19

How do plants and animals obtain phosphorus?

Answer 19

Plants absorb it from soil

Question 20

What do decomposers do in the phosphorus cycle?

Answer 20

They release phosphorus by breaking down dead matter

Question 21

What does phosphorus do in plants?

Answer 21

It helps form roots and flowers

Question 22

How do humans affect the phosphorus cycle?

Answer 22

By using fertilizers that cause runoff into water systems

Question 23

What is eutrophication?

Answer 23

A process where excess nutrients cause algal blooms that reduce oxygen and harm aquatic life

Question 24

What causes eutrophication in the phosphorus cycle?

Answer 24

Phosphorus runoff from fertilizers leads to overgrowth of algae

Question 25

What are sources of sulfur in the atmosphere?

Answer 25

Burning fossil fuels and volcanic eruptions release sulfur dioxide (SO2)

Question 26

How does sulfur return to earth?

Answer 26

Through acid rain or the weathering of rocks

Question 27

How does sulfur move through ecosystems?

Answer 27

Through food chains and decomposition

Question 28

How is sulfur returned to the soil?

Answer 28

From decaying organisms and weathered rocks

Question 29

How do humans use sulfur in the cycle?

Answer 29

By extracting it from fossil fuels for industrial use

Question 30

What is a primary pioneering population?

Answer 30

The first organisms to colonize a barren area

Question 31

What is a secondary pioneering population?

Answer 31

Organisms that move into an area after a disturbance

Question 32

What is an autotroph?

Answer 32

An organism that produces its own food

Question 33

What is a heterotroph?

Answer 33

An organism that obtains its food by consuming other organisms.

Question 34

Types of consumers (heterotrophs)

Answer 34

Primary

Question 35

What is a primary consumer?

Answer 35

An herbivore that feeds on producers.

Question 36

What is a secondary consumer?

Answer 36

A carnivore or omnivore that feeds on primary consumers.

Question 37

What is a tertiary consumer?

Answer 37

A carnivore or omnivore that feeds on secondary consumers.

Question 38

Define a food chain

Answer 38

A single pathway describing how energy flows from one organism to another.

Question 39

Define a food web

Answer 39

A network of interconnected food chains in an ecosystem

Question 40

In a food chain or food web

Answer 40

which way do the arrows point?

Question 41

What is an energy pyramid?

Answer 41

A graphical representation showing the decrease in energy as it moves up trophic levels.

Question 42

Explain the Rule of 10 in an energy pyramid

Answer 42

Only about 10% of the energy from one trophic level is transferred to the next level; the remaining 90% is lost as heat.

Question 43

Define symbiosis

Answer 43

A close and long-term interaction between two different biological organisms.

Question 44

What is mutualism?

Answer 44

A symbiotic relationship where both organisms benefit.

Question 45

Example of mutualism

Answer 45

Bees pollinating flowers (bees get nectar

Question 46

What is commensalism?

Answer 46

A symbiotic relationship where one organism benefits and the other is neither helped nor harmed.

Question 47

Example of commensalism

Answer 47

Barnacles on a whale (barnacles get a place to live/feed

Question 48

What is parasitism?

Answer 48

A symbiotic relationship where one organism (the parasite) benefits at the expense of the other (the host).

Question 49

Example of parasitism

Answer 49

A tick feeding on a dog (tick benefits

Question 50

Problem associated with ozone depletion

Answer 50

A hole in the ozone layer.

Question 51

What causes ozone depletion?

Answer 51

Chlorofluorocarbons (CFCs) in the atmosphere from propellants and refrigerants/coolants (Freon).

Question 52

Effects of ozone depletion

Answer 52

Increased UV radiation

Question 53

Solution for ozone depletion

Answer 53

Replace CFCs.

Question 54

Main cause of climate change

Answer 54

Greenhouse gases from burning coal and other fossil fuels.

Question 55

Major greenhouse gases

Answer 55

Carbon dioxide (CO2)

Question 56

Effects of climate change

Answer 56

Regional climate shifts

Question 57

How does climate change affect water and oceans?

Answer 57

Changes in water availability and ocean acidification.

Question 58

Explain ocean acidification

Answer 58

Increased carbon dioxide causes calcium carbonate in shelled organisms to soften.

Question 59

What is eutrophication?

Answer 59

The excessive richness of nutrients in a lake or other body of water

Question 60

What causes eutrophication?

Answer 60

Increased nitrogen and phosphorus in water

Question 61

Effects of eutrophication

Answer 61

Algal bloomsm harm to aquatic life

Question 62

What is an organism?

Answer 62

A single living being.

Question 63

What is a population?

Answer 63

A group of individuals of the same species living in the same area at the same time.

Question 64

What is a community?

Answer 64

All the different populations of organisms living and interacting in a particular area.

Question 65

What is an ecosystem?

Answer 65

All the living organisms (biotic factors) in an area interacting with each other and with their non-living environment (abiotic factors).

Question 66

What is a biome?

Answer 66

A large region of Earth characterized by a distinct climate and dominant plant life (e.g.

Question 67

What is a biosphere?

Answer 67

The sum of all ecosystems on Earth; the part of Earth where life exists.

Question 68

What are trophic levels?

Answer 68

The feeding positions in a food chain or food web representing the different levels at which organisms obtain energy.

Question 69

Examples of trophic levels

Answer 69

Producers primary consumers secondary consumers tertiary consumers decomposers.

Question 70

What is biomass?

Answer 70

The total mass of living organisms in a given area or trophic level.

Question 71

How does biomass change in an energy pyramid?

Answer 71

Biomass generally decreases at each successive trophic level due to energy loss.

Question 72

What is logistic growth?

Answer 72

When a population's growth skyrockets expontentially, slows, then stops,creating a sort of s shape.