Log inSign up for FREE
Library

1.6 Phosphorus Cycle

Last updated 7 months ago
12 questions
1

Submit your Phosphorus Cycle table here

PHOSPHORUS CYCLE
Although nitrogen and carbon exist as gases, other elements collect in rocks and soil and are not found as a gas – such as Phosphorus. Phosphorus is important to life because it is found in DNA (your genetic information) and ATP (which is what all living things get energy from!). Without Phosphorus life would not be possible! Today we will be following the steps of the Phosphorus cycle.


The main phosphorus reservoir (place where phosphorus collects) is rock and soil so this is where the cycle begins – in the picture the main reservoir is the volcano.


Erosion occurs as water runs over rock, washing the phosphorus into rivers and streams.


Then, phosphorus mixes with oxygen to form phosphate and enters a major body of water, depicted here as a lake.

Next, the water containing phosphate is absorbed (taken in) by the plants and are used to make DNA & ATP.

In order for animals to get the phosphate they need, they must consume (eat) plants.

When plants and animals release waste or die, the phosphate in their bodies decompose and the phosphate is returned to the soil or water – at this point it can be reabsorbed by plants once again!

Large amounts of phosphate is carried by rivers and streams as runoff to the ocean.

This phosphate then concentrated (settles) in marine sediment - creating "ocean rocks". Just like on land, aquatic plants then absorb the Phosphorus and the animals eat the plants to get the Phosphorus they need.

As we have seen, the atmosphere is not involved in the phosphorus cycle because it is not found in a gaseous form. This is very different from the carbon and water cycle were the atmosphere is a main part of each cycle.
1

Why is Phosphorus an important molecule for life?

1

How do animals receive phosphorus?

1

What is the major reservoir of the phosphorus cycle?

1

What happens to Phosphorus that erodes from rock and soil?

1

What happens to the phosphates when plants and animals die?

1

What is different about the Phosphorus cycle when compared to the water and carbon cycles?

1

Put the statements in the order they would occur.

  1. There is an increase on nitrogen/phosphorus in the water
  2. Fertilizer is washed into lakes and oceans due to runoff
  3. Plants and animals die due to blocked sunlight and a decrease of oxygen in water
  4. Overgrowth of Algae
  5. Farmers use artificial fertilizers containing nitrogen on their crops
  6. A deadzone is created
1

How do plants receive phosphorus?

(Select 2 correct answers)

1

What happens to the phosphorus that is carried by runoff to the oceans?

1

Match the terms with their definitions

Draggable itemCorresponding Item
Decomposition
The main phosphorus reservoir
Plant/animal absorbtion/consumption
Water moving over rocks, washing phosphorus into rivers and streams
Rocks and soil
Where phosphorus mixes with oxygen to make phosphates
Fertilizer runoff
Water containing phosphates is absorbed/Plants are eaten to get the phosphate they need
Erosion
Excess nutrients runoff into streams and lakes causing toxic algal bloom
Phosphates in water
Phosphorus is broken down in waste and returned to water or soil
1

Draw the arrows for the phosphorus cycle here.