The Nitrogen Cycle and the Phosphorus Cycle

The Nitrogen Cycle and the Phosphorus Cycle

Fill in the Blank

Type the correct answer in the box. Spell all words correctly.

How is molecular nitrogen (N2) utilized by plants and animals?

Before it can be utilized by plants and animals, molecular nitrogen (N2) must be converted by microbes that use N2 as a replacement for _________________.

Multiple Choice

Plants and animals need nitrogen to make __________.

• Protein
• Carbohydrates
• Lipids
• Minerals

Multiple Choice

What process occurs when dead plant and animal matter decomposes and nitrogen is released back into the atmosphere?

• Assimilation

• Fixation

• Ammonification

• Denitrification

Multiple Choice

What is the process of combining nitrogen gas with other elements to make nitrogen into usable compounds?

• nitrogen composition

• nitrogen fixation

• ammonia

• denitrification

Multiple Choice

How is nitrogen "fixed" into a usable form for plants?

• Through action of bacteria only

• Through lightning only

• Through action of bacteria and lightning

• Through photosynthesis

Multiple Choice

A correct path that nitrogen could take would be

• air -> animals -> plants -> bacteria

• animals -> air -> bacteria -> plants

• bacteria -> air -> plants -> animals

• air -> bacteria -> plants -> animals

Multiple Choice

What is the formula for atmospheric nitrogen?

• N

• N₂

• NH₃

• NO₃

Multiple Choice

How do animals get the nitrogen they need?

• From the air they breathe

• From the water they drink

• From the food they eat

• From the sun

Multiple Choice

What converts nitrogen gas into a usable form for plants and animals?

• bacteria

• rain

• fungi

• car exhaust

Multiple Choice

Nitrification happens in the ______

• Air 
• Soil 
• Ground Water 
• Plants 

Multiple Choice

The process in which Nitrogen circulates and is recycled is called ____________

• The nitrogen cycle
• The water cycle
• The carbon cycle
• Nitrogen Fixation 

Multiple Choice

What happens when organisms die and decay? 

• Their bodies are lifted up
• Their nitrogen returns to the soil
• they keep their nitrogen
• They stay on earth forever

Multiple Choice

After plants and animals contain nitrogen, what puts it back into atmosphere and soil?

• decomposition
• precipitation
• condensation
• bacteria

Multiple Choice

Plants and animals cannot use nitrogen directly from the air.

• True
• False

Multiple Choice

Organisms that need nitrogen to survive

• only plants
• only animals
• only bacteria
• all living organisms

Multiple Choice

Organisms that break down dead plants & animals and release nitrogen back into atmosphere...

• bacteria
• plants
• animals
• producers

Multiple Choice

How much of the atmosphere is composed of nitrogen gas?

• 87%
• 38%
• 78%
• 21%

Multiple Choice

How much of the atmosphere is composed of nitrogen gas?

• 87%
• 38%
• 78%
• 21%

Multiple Choice

In general, algal blooms occur when

• toxins accumulate in shellfish.

• nutrients decrease in the water.

• nutrients increase in the water.

Multiple Choice

An algal bloom is the rapid growth of a population of

• fungi

• protozoans

• algae

Multiple Choice

Too much phosphorus in waterways (rivers, lakes) can lead to___________.

• eutrophication

• Nothing

• Death

• diseases

Multiple Choice

Which of the following statements is true of the phosphorus cycle?

• Phosphorus enters the atmosphere as phosphates.
• The phosphorus cycle utilizes the processes of erosion, and weathering.
• Phosphates are used in carbohydrate and glucose storage.
• The phosphorus cycle utilizes bacteria to breakdown phosphates and make them available for plants.

Multiple Choice

_____ brings phosphorous into our waterways. .

• precipitation
• runoff
• transpiration
• condensation

Multiple Choice

True or false: Phosphorous can enter the atmosphere

• True

• False

Multiple Choice

What is the phosphorus' symbol on the periodic table?

• P

• pH

• Ph

• H

Multiple Choice

Which nutrient is not cycled through the atmosphere and stays only on ground level?

• carbon
• nitrogen
• phosphorus
• water

Multiple Choice

This is released by the weathering of rocks.

• Carbon
• Oxygen
• Phosphorus
• Nitrogen

Multiple Choice

What role do decomposers play in the phosphorous cycle?

• absorb phosphorous 
• release phosphorous into atmosphere
• return phosphorous into the soil
• combustion

Multiple Choice

Phosphorous is passed from plants to ____ who eat them

• plants
• animals
• scavengers

Multiple Choice

This is NOT a part of the phosphorus cycle.

• Phosphate is incorporated into sedimentary rocks

• Phosphate bound to soil

• Atmospheric phosphate

• Phosphate is absorbed from the soil by plants

Multiple Choice

What nutrients increase the rate of algae growth and reproduction in aquatic ecosystems?

• nitrates and phosphates

• sulfates and ammoniates

• philates and sulfates

• phosphates and communicates

Multiple Choice

What causes eutrophication of a lake?

• a dramatic drop in phosphate and nitrate levels

• a dramatic increase in phosphate and nitrate levels

• increased indicator tests taken at the lake

• a high fish population in the lake

Multiple Choice

Which statement best explains this image?

• The west coast is the source of the most nutrients due to colonization and development of land.

• The midwest is the source of most nutrients due to farming and fertilizer use.

• The east coast is the source of most nutrients due to flooding of fields.

Multiple Choice

Fertilizer, sewage, and animal feces can wash in to water, leading to...

• thermal pollution

• eutrophication

• photosynthesis

• noise pollution

Multiple Choice

An increase in the amount of nutrients in a lake is known as

• calcification

• cellular respiration

• eutrophication

• photosynthesis

Multiple Choice

The size of dead zones will ________ with more nitrogen run-off.

• Increase

• Stay the same

• Decrease

Multiple Choice

The long term effects of a dead zone includes all of the following except for

• Fisherman may struggle to catch any fish.

• The crops of farmers stop growing.

• The health of the fish population declines.

• There is an increase in the population of decomposers such as bacteria.

Multiple Choice

In a dead zone, _________ levels are really low such that living organisms are not able survive.

• nitrogen

• oxygen

• fertilizer

• carbon dioxide

Multiple Choice

True or False: Fertilizers used for growing crops always stay within the boundaries of the farm.

• True

• False

Multiple Choice

Which of the following is NOT a source of nitrates and phosphates into a river?

• Fertilizers

• Animal waste

• Wastewater

• Burning fossil fuels