B3 Cycles In Ecosystems

Question 1

What substances are essential for life on earth?

Answer 1

Water and Carbon

Question 2

What is an ecosystems?

Answer 2

A community of living organisms in an area as well as the non living non conditions.

Question 3

How are Carbon and water recycled?

Answer 3

Through biotic and abiotic components of the ecosystem.

Question 4

What are the biotic parts of the ecosystem?

Answer 4

Living organisms

Question 5

What are the abiotic parts of an ecosystem?

Answer 5

Air, rocks and soil

Question 6

Where do water and Carbon come from?

Answer 6

They are passed through both living organisms and things like air, rock and soil in a continuous cycle.

Question 7

What does the carbon cycle show?

Answer 7

How Carbon is recycled.

Question 8

Why is Carbon essential?

Answer 8

All living things are made from Carbon and there is fixed amount of carbon in the world.

Question 9

What are fossil fuels made from?

Answer 9

Decayed plant and animal matter

Question 10

What happens to plants and animals when they die?

Answer 10

They are decomposed by microorganisms and the Carbon is released into the soil.

Or they are made into useful products.

Question 11

What is the Carbon cycle powered by?

Answer 11

Photosynthesis

Question 12

What do green plants use Carbon from CO2 to make?

Answer 12

Carbohydrates, lipids and proteins

Question 13

How are Carbon compounds passed into animals?

Answer 13

The Carbon in the plants is passed along the food chain to animals by eating.

Question 14

How is CO2 released into the air?

Answer 14

Respiration of plants and animals

Question 15

What are decomposers?

Answer 15

Microorganisms such as fungi and bacteria, that breakdown dead plants and animals.

Question 16

How do decomposers breakdown dead material?

Answer 16

They release enzymes that catalyse the breakdown of dead material into smaller molecules.

Question 17

How do decomposers release CO2 back into the atmosphere?

Answer 17

Respiration as they breakdown the material.

Question 18

What happens when we burn wood or fossil fuels?

Answer 18

CO2 is released back into the atmosphere

Question 19

Why is decomposition needed in a habitat?

Answer 19

So that nutrients can be returned to the soil and waste matter doesn’t just pile up.

Question 20

Suggest two reasons why chopping down trees can increase the concentration of CO2 in the air. (2 marks)

Answer 20

Not as much CO2 in the air being used for photosynthesis (1 mark)
Microorganisms involved in decomposition of dead trees release CO2 into the air through respiration (1 mark)

Question 21

As well as Carbon what else is constantly recycled?

Answer 21

Water.

Question 22

How is water turned into water vapour?

Answer 22

Energy from the sun makes water evaporate from the land and sea and turn into water vapour.

Question 23

What is transpiration ?

Answer 23

Water evaporation from plants.

Question 24

What happens to water vapour to cause it to form clouds?

Answer 24

Warm water vapour is carried upwards, when it gets higher it cools and condenses to form clouds.

Question 25

How is water released from the clouds?

Answer 25

Precipitation onto land (rain, snow, hail)

Question 26

How do plants get fresh water for things like photosynthesis?

Answer 26

Some of the precipitation is absorbed by soil and taken up by the plant roots.

Question 27

What happens to the water that is taken up from the soil by plants?

Answer 27

Some becomes part of the plants tissues and is passed along to animals in food chains.

Question 28

How do animals return water to the soil and atmospheres?

Answer 28

By excretion

Question 29

Name 3 ways animals excrete water back into the atmosphere?

Answer 29

Urinating
Sweating
Breathing out

Question 30

What happens to water that doesn’t get absorbed by the soil?

Answer 30

It will runoff into streams and rivers

Question 31

What happens to the water that runs off into rivers and streams?

Answer 31

It drains back into the sea, before its evaporates again.

Question 32

Formula for calculating percentage mass transferred in a cycle.

Answer 32

Percentage of mass transferred = amount of loss over amount taken in times 100

Question 33

In the water cycle, how does water move from land into the air? (1 mark)

Answer 33

Evaporation/transpiration

Question 34

How does the water cycle benefit plants and animals? (1 mark)

Answer 34

By providing then with fresh water.