Homework

• Revise test on energy and organisms

• Green rev guide pp33,34,35

• Test date =

Energy Transfers B1 5.2

Text p. 96

What am I?

Write down your answers to these definitions.

What am I?

1) I make my own food using sunlight and raw materials.

2) I obtain my food by eating other living organisms.

3) I only eat plant material.4) I obtain my food only from animals.5) I eat dead plant or animal material.

What am I?6) I am a simple diagram showing what eats

what.

7) I am a more complicated (and more realistic) version of this diagram.

8) I am the original source of energy for all living things.

9) I am not always pyramid shaped as the size of the organism is not taken into account

10)I am the best of the 2 pyramids

Energy Transfers B1 5.2 Objectives

• Materials and energy are lost in an organisms waste materials

• Energy is used in movement

• Energy is lost as heat to the environment

• Maintaining a constant body temperature results in more heat loss and more energy use

Energy loss in food chains

Text p. q97

• Rearrange the key words so they are in the correct places. Write out the correct version in your exercise book.

The amounts of growth and movement contained in living things always get less at each stage of a food respiration from waste onwards. Biomass is lost as producers products and used to release energy in biomass. This is used for temperature and to control body energy. Only a small amount is used for chain

• Answer Q 2

Answer to Q 2 page 97

• Q2 answer – most sunlight energy hitting the Earth is not captured by plants. Some hits bare ground, roads etc. Some light is reflected from the surface of plants. 50% of the light that does hit plants can’t be absorbed as it is the wrong wavelength. So only a little is used in photosynthesis. Not all plant biomass eaten by animals is digested, some is broken down in respiration to release energy, energy is used for movement and control of body temperature. Only small amount of energy is used for growth to produce new biomass in animals.

Why do some animals need more energy?

Mammals and birds are able to regulate their body temperature. This has many advantages but it uses lots of energy.

Other animals, such as snakes, lizards and fish, are unable to regulate their body temperature, so need less energy.

Would it be more energy efficient to farm snakes for food than chickens?

Sankey diagram list what you can conclude? (2 mins)

Questions to answer using text pages 96 & 97

• Why do… Herbivores lose most energy in their faeces and urine?

• Why do… Carnivores lose little energy in faeces and urine in comparison to herbivores?

• Why do… Cold-blooded animals lose only a small amount of heat compared to warm-blooded animals?

Sankey diagram generator

• AQA disc 3.2 simulation ‘Energy losses’

• predicting what the Sankey diagram will look like for a new animal

• Could use show me board to guess energy use/loss for each of these categories per animal;

• Food, growth,excrement, movement, heat

Do plants lose heat energy?

• Using data from germinating peas experiment with the data logger: complete worksheet

Syllabus points• • The mass of living material (biomass) at each stage in a food

chain• is less than it was at the previous stage.• • The amounts of material and energy contained in the biomass of• organisms is reduced at each successive stage in a food chain• because:• − some materials and energy are always lost in the organisms.• waste materials• − respiration supplies all the energy needs for living processes,• including movement. Much of this energy is eventually lost as• heat to the surroundings• − these losses are especially large in mammals and birds whose• bodies must be kept at a constant temperature which is usually• higher than that of their surroundings.

Bucket of sand

• What does the bucket of sand represent?

• What do the sieves represent?

• Why have Trays?

A typical food chain

• Hold the first sieve (plants) over a tray.• Pour the sand into the sieve.• Person holding the second sieve (Herbivore)

has to move (safely) from the far end of the room to the tray and any sand remaining in the first sieve is poured into the second sieve.

• Repeat with each sieve up the foodchain.• How much sand is in the tray? • What does this represent?