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Cycles within ecosystems

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Question 5

The diagram shows the nitrogen cycle. The letters A to F represent different processes in the nitrogen cycle.

A flowchart showing the nitrogen cycle. Six boxes representing nitrogen reservoirs are connected by arrows. Top: "nitrogen gas in the atmosphere". Bottom right: "nitrates in the soil". Bottom center: "ammonium compounds in the soil". Left: "nitrogen compounds in plants". Far left: "nitrogen compounds in animals". Middle left: "nitrogen compounds in dead organic matter and waste". Arrow F goes from "nitrogen gas in the atmosphere" to "ammonium compounds in the soil". Arrow A goes from "nitrates in the soil" to "nitrogen compounds in plants". Arrow B goes from "nitrogen compounds in plants" to "nitrogen compounds in animals". Two unlabeled arrows point from plants and animals to "nitrogen compounds in dead organic matter and waste". Arrow C goes from "nitrogen compounds in dead organic matter and waste" to "ammonium compounds in the soil". Arrow D goes from "ammonium compounds in the soil" to "nitrates in the soil". Arrow E goes from "nitrates in the soil" to "nitrogen gas in the atmosphere".

a.

Complete the table by naming the process represented by each letter. The entry for letter B has been done for you.

LetterName of process
A
Bfeeding
C
D
E
F
[5]
b.

Some of the nitrogen in plants is found in organic macromolecules. Name two nitrogen-containing macromolecules found in plants.

[2]
c.

Name the simpler monomer molecules that are linked to form proteins.

[1]
d.

Describe how the intensive use of nitrogen-containing fertilisers on agricultural land can lead to eutrophication in nearby aquatic ecosystems, and explain the consequences of this process on aquatic life.

[7]

Cycles within ecosystems Questions

  1. IGCSE
  2. /Biology
  3. /Cycles within ecosystems