9/17 Step 2 Phosphorus Cycle Reading AP

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. Erosion occurs as water runs over rock, washing the phosphorus into rivers and streams. At this point, 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 phosphorus in their bodies decompose and the Phosphorus is returned to the soil or water – at this point it can be reabsorbed by plants once again!

Large amounts of phosphorus is carried by rivers and streams as runoff to the ocean and is then concentrated (settles) and compresses to become marine sediment (rock). 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 where the atmosphere is a main part of each cycle.

1

Define each step of the phosphorus cycle. Use the "T" tool to type into the box.

1

What is the major reservoir of the phosphorus cycle?

1

Why is Phosphorus an important molecule for life?

1

How do animals receive phosphorus?

1

How do plants receive phosphorus? (More than one choice)

1

What happens to Phosphorus that erodes from rock and soil?

1

What happens to the phosphates when plants and animals die?

1

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

1

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

1

Define each step of the phosphorus cycle. Use the "T" tool to type into the box.

What is the major reservoir of the phosphorus cycle?

Why is Phosphorus an important molecule for life?

How do animals receive phosphorus?

How do plants receive phosphorus? (More than one choice)

What happens to Phosphorus that erodes from rock and soil?

What happens to the phosphates when plants and animals die?

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

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

Similar to the nitrogen cycle, excess phosphorus in water ecosystems can cause