Lesson 2.2

• Biologie
• Middelbare school
• vwo
• Leerjaar 4

Nutrient cycling

Plants transform energy from the sun into:

1. nuclear energy
2. solar energy
3. chemical energy
4. mechanical energy

If the decomposers were removed from an ecosystem, what would most likely occur?

1. Energy from the sun would not be absorbed by plants
2. Carnivores would have no source of energy
3. Essential elements would not be available to plants
4. Herbivores would lose their source of energy and nutrients

Use the food chain below to answer the next question.

Grass → Prairie dog → Rattlesnake → Hawk

What sequence below best represents how much energy is passed from one organism to the next in the food chain above?

1. 100% → 10% → 1% → 0.1%
2. 100% → 50% → 25% → 12.5%
3. 100% → 75% → 50% → 25%
4. 100% → 90% → 80% → 70%

03:57

Photosynthesis

Animal respiration

Plant respiration

Fossil fuels

Atmospheric nitrogen (N2)

Denitrifying bacteria

Nitrifying bacteria

Ammonium (NH4+

In an environment, elements such as carbon are usually

1. converted into nuclear energy
2. synthesized and remain as fossil fuels
3. converted into nonrenewable resources
4. recycled and reused by other organisms

Which of the following statements is NOT true about this diagram?

1. Carbon dioxide and oxygen are used by producers in the ecosystem
2. Living organisms remove and replace oxygen back into the atmosphere.
3. Consumers generate oxygen and consume carbon dioxide
4. Living organisms generate carbon dioxide which is used by other organisms

Would you say that the transfer of energy through the ecosystem was a cyclical
process where the energy is reused or a flow in one direction?
Give reasons for your choice.

Organic farmers do not use artificial fertilisers to put nitrates into the soil.
Explain why organic farmers often keep farm animals, even if they mainly grow crops such as wheat.