4.5 & 6 Flashcards
Why isn’t all the energy obtained from the sun by a producer transferred into biomass?
Only 1% of sunlight is converted to energy in chemical stores
Most of the light is reflected
Energy is used for respiration and the rest for biomass
How much chemical energy is transferred into biomass when consumers consume?
10%
How is biomass lost when consumers consume?
- Not all the organism is eaten (e.g. bones aren’t eaten)
- Some biomass is used for respiration - cases thermal energy transfer as the ATP produced allows muscle movement converting energy to thermal energy
- egestion, excretion
What is egestion?
Removal of undigested waste from an organism (faeces)
E.g. hair and teeth cannot be digested
What is excretion?
Waste products produced by the BODY are lost through excretion.
E.g. urine
What is nutrient cycling?
Plants take nutrients from the soil, passed to animals and then back into the soil through decomposition. Here, materials are passed from biotic to abiotic factors.
What are the uses and characteristics of carbon?
Used to make DNA, fats, CHO, protein,
Cycles between atmosphere, living organisms and fossil fuels. Trapped in oceans. rocks, ice
What is nitrifying bacteria?
Coverts ammonia of dead animals and plants into nitrates in the soil.
What is denitrifying bacteria?
Converts nitrates in the soil into nitrogen gas.
What is nitrogen-fixing bacteria?
Converts nitrogen into nitrates in plant legume root nodules (have a mutualistic relationship with legumes)
Summarise the nitrogen cycle.
- Nitrogen from air goes to plants via nitrogen-fixing bacteria
- Nitrogen is also fixed via lightning
- Plants make proteins, plant eaten by animals who now have nitrogen
- Plants and animals die, they decompose and nitrogen released into soil as ammonia.
- Animals also release nitrogen back through faeces and urine.
