B17 - Organising An Ecosystem

Question 1

How can you write a food chain?

Answer 1

Weeds—>tadpoles—>beetles
Arrow meaning ‘the transfer of energy’

Question 2

What do all food chains start with ?

Answer 2

All food chains begin with an organism that can photosynthesise (i.e. a green plant, algae or cyanobacteria) which makes food (glucose) by photosynthesis.

These are called producers - they produce their own food using the energy from the sun

Question 3

When a green plant produces glucose, some of it it used to make other…..

Answer 3

Biological molecules in the plant

Question 4

What are biological molecules ?

Answer 4

They are the plants biomass - the mass of living material

Question 5

Whats the plants biomass ?

Answer 5

Its the mass of living material and can be thought of as energy stored in a plant

Biomass means the mass of living material at a stage/trophic level in a food chain.

Question 6

When is energy transferred through living organisms in an ecosystem

Answer 6

Energy is transferred through living organims in an ecosystem when organisms eat other organisms

Question 7

What are producers eaten by ?

Answer 7

Producers are eaten by primary consumers.

Question 8

What are primary consumers eaten by ?

Answer 8

Primary consumers are eaten by secondary consumers

Question 9

What are secondary consumers eaten by ?

Answer 9

Secondary consumers are eaten by tertiary consumers

Question 10

What are consumers ?

Answer 10

Consumers are organisms that eat other organisms ,
‘Primary’ means ‘first’, so primary consumers are the first consumers in a food chain. Secondary consumers are second and tertiary consumers are third.

Question 11

Give an example of a food chain

Answer 11

5000 dandelions feeds 100 rabbits which feeds 1 fox
Producer, Primary consumer, Secondary consumer

Question 12

Each level of food chain is called a

Answer 12

Trophic level

Question 13

Does biomass increase or decrease from one trophic level to the next ?

Answer 13

Biomass decreases from one trophic level to the next, just like the amount of energy.

Question 14

What are predators ?

Answer 14

Consumers that hunt and kill other animals

Question 15

What are decomposers ? And how do they do their job?

Answer 15

Decomposer are bacteria and fungi which break down dead plant and animal matter.

Decomposers secrete enzymes onto the surface of the dead organisms

The matter is broken down into soluble food molecules, which are then absorbed into the microorganism by diffusion.

Question 16

What are scavangers ?

Answer 16

Feed on dead animals. For example, crows, vultures and hyenas are scavengers.

Question 17

What is prey ?

Answer 17

The animals that the predators feed on

Question 18

What are the 3 environmental changes that can affect the distribution ?

Answer 18

A change in the availibility of water e.g. The distribution of some animal and plant species in the tropics changes between the wet and the dry seasons - i.e. the times of year where there is more or less rainfall, and so more or less water available.

A change in the temp e.g. The distribution of bird species in Germany is changing because of a rise in average temperature.

A change in the composition of atmospheric gases for e.g. the distribution of some species changes in areas where there is more air pollution.

Question 19

What is the water cycle ?

Answer 19

1) Energy from the Sun makes water evaporate from the land and sea, turning it into water vapour. Water also evaporates from plants this is known as transpiration

2) The warm water vapour is carried upwards (as warm air rises). When it gets higher up it cools and condenses to form clouds.

3) Water falls from the clouds as precipitation (usually rain, but sometimes snow or hail) onto land, where it provides fresh water for plants and animals.

4) It then drains into the sea, before the whole process starts again.

Question 20

What is decay ?

Answer 20

Microorganisms break down plant and animal material and waste to get energy. This process is called decay.

Question 21

What is compost ?

Answer 21

Compost is decomposed organic matter that is used as a natural fertiliser for crops ans garden plants

Farmers and gardeners try to provide the ideal conditions for quick decay to make compost

Question 22

Whats responsible for decay (decompostition) ?

Answer 22

Microorganims such as bacteria and fungi as well as detritus feeders

Question 23

What are the 4 things that effect the rate of decay ?

Answer 23

1) TEMPERATURE - Warmer temperatures make things decompose quicker because they increase the rate that the enzymes involved in decomposition work at. If it’s too hot though, decomposition slows down or stops because the enzymes are destroyed and the organisms die.
Really cold temperatures slow the rate of decomposition too.

2) OXYGEN AVAILABILITY - Many organisms need oxygen to respire, which they need to do to survive. The microorganisms involved in anaerobic decay

3) WATER AVAILABILITY - Decay takes place faster in moist environments because the organisms involved in decay need water to carry out biological processes.

4) NUMBER OF DECAY ORGANISMS - The more microorganisms and detritus feeders there are, the faster decomposition happens.

Question 24

What is biogas made out of ?

Answer 24

Biogas is mainly mad eout of methane, which can be burned as a fuel

Question 25

How is biogas made ?

Answer 25

Biogas is made by anaerobic respiration of waste material

It is made in a simple fermenter called a digester or generator

Question 26

Why do biogas generators need to be kept at a constant temperature ?

Answer 26

To keep the microorganisms respiring

Question 27

Why cant biogas be stored as a liquid ?

Answer 27

Because it needs too high a pressure to be stored, so it has to be used straight away - for heating, cooking, lighting, or to power a turbine to generate electricity

Question 28

What are the 2 main types of biogas generators ?

Answer 28

Batch generators and continous generators

Question 29

What do batch generators do ? And what do continous generators do ?

Answer 29

Batch generators make biogas in small batches.
They’re manually loaded up with waste, which is left to digest, and the by-products are cleared away at the end of each session.

Continuous generators make biogas all the time.
Waste is continuously fed in, and biogas is produced at a steady rate. Continuous generators are more suited to large-scale biogas projects.

Question 30

What do all biogas generators have to have ?

Answer 30

1) and inlet for waste material to be put in

2) an outlet for the digested material to be removed through

3) an outlet so that the biogas can be piped to where it is needed