B4 e-h Pig

• What’s wrong with this food chain?

• Arrows pointing wrong way

• How do you work out biomass?

• Number of organisms x average (dry) mass

• List 2 ways energy is lost as you move up a food chain

• Some parts don’t get eaten

• Some lost as faeces

• Some used in respiration (movement, keeping warm etc)

• Why can farmers make more money by keeping battery hens in cages than they can from free range?

• Less energy is lost in moving and keeping warm so farmers can feed them less

• Name 2 biofuels

• Biogas (methane)

• Bioethanol

• Wood

• How do you make biogas?

• Fermentation• By bacteria• In a digester

• Why do farmers use pesticides?

• So pests don’t eat crops• (Less of the crop’s energy is lost to pests is a

better answer)

• What is biological control?

• A natural predator eats the pest

• What are the advantages of biological control?

• No toxic chemical• Useful insects not

harmed• Top predators not

poisoned

• What 3 conditions do decomposers need to grow?

• Oxygen

• Water

• Warmth

• Why does adding sugar or salt preserve food?

• Removes water using osmosis

• Name 2 uses of decomposing microbes?

• Making compost• Breaking down

sewage

• How does carbon get into plants?

• Photosynthesis

• List 3 ways carbon is put back into the atmosphere?

• Respiration by animals

• Respiration by plants• Respiration by

decomposers (decomposition)

• Combustion

• Why is there more carbon dioxide in the atmosphere in the winter?

• Less photosynthesis (fewer leaves)

• More combustion (heating)

• What other element is recycled in nature?

• nitrogen