5: Energy Transfer Flashcards
(21 cards)
Ecosystem definition?
All of the organisms living in a particular area and all the abiotic conditions
Producers definition?
Organisms that make their own food
Biomass definition?
The mass of living material / the chemical energy stored in an organism
What can biomass be measured in terms of?
the mass of carbon that an organism contains or the dry mass of its tissue per unit area
How to work out the mass of carbon?
50% of the dry mass
Gross primary production definition?
the total amount of chemical energy converted from light energy by plants in a given area
Net primary production equation?
NPP = GPP - R
What is NPP used for?
the energy available to the plant for growth and reproduction
Net production of consumers equation?
N = I - (F + R)
% efficiency of energy transfer equation?
net production of trophic level / net production of previous trophic level *100
How to increase efficiency (NPP and NP)?
Simplification of food webs - chemical pesticides, biological agents
Reducing respiratory losses
What is saprobiotic nutrition?
obtaining nutrients from dead organic matter and animal waste using extracellular digestion
What are organic molecules broken down into by extracellular digestion?
Inorganic ions
What are mycorrhizae?
Fungi in a symbiotic relationship with the roots of plants
Hyphae connect to the plants roots - increasing the surface area for absorption
Fungi obtain organic compounds from the plant
What is nitrogen used for?
Making proteins and nucleic acids
Nitrogen fixation?
Nitrogen fixing bacteria convert nitrogen in the atmosphere into ammonia - forms ammonium ions in solution
Some found in root nodules of leguminous plants - mutualistic relationship (plant gets nitrogen compounds, bacteria gets carbohydrates)
Ammonification?
Nitrogen containing compounds from dead organisms and waste are turned into ammonia by saprobionts
Nitrification?
Nitrifying bacteria coverts ammonium ions in the soil into nitirites and then nitrates
Denitification?
Nitrates in the soil are converted into nitrogen gas by denitrifying bacteria - respire using nitrates under anaerobic conditions
What other ways can nitrogen get into an ecosystem?
Lightning, artificial fertilisers
What is eutrophication?
Mineral ions leached from fertilised fields, rapid growth of algae blocks light from plants below, can’t photosynthesise - die, bacteria aerobically respire - fish die
