Energy and Ecosystems Flashcards
What is a carnivore, herbivore, and omnivore?
Carnivore = eats other animals
Herbivore = eats plants
Omnivore = eats both other animals and plants
What do plants synthesise organic compounds from?
Plants synthesise organic compounds from atmospheric, or aquatic carbon dioxide.
What are sugars synthesised by plants used for?
Most sugars synthesised by plants are used as respiratory substrates - the rest are used to make biological molecules, forming the biomass of the plant.
What is meant by biomass?
Biomass can be measured in terms of mass of carbon or dry mass of tissue per given area.
What is meant by dry biomass?
Dry biomass is the chemical energy store in an organism which can be measured by the process of calorimetry.
What is the process of calorimetry?
A dry sample is weighed and burnt in pure oxygen within a sealed chamber - the temperature increase of the fixed volume of water is used to calculate the energy released.
What is gross primary production (GPP)?
GPP is the total quantity of chemical energy stored in plant biomass, in a given area or volume.
What is net primary production (NPP)?
NOP is the chemical energy store in plant biomass after respiratory losses to the environment are taken into account.
What is the NPP equation?
NPP=GPP-R (kJm^-2yr^-1)
What is net production (N)?
Net production is the total chemical energy consumers store after energy losses to respiration and excretion.
What is the equation of net production?
N=I-(F+R) (kJm^-2yr^-1)
What is primary and secondary productivity?
Primary and secondary productivity is the rate of primary or secondary production, measured as biomass in a given area in a given time. (kJha^-1yr^-1).
What is the equation for percentage efficiency of energy transfer from one trophic level to another?
(energy after transfer / energy before transfer) x 100
How are farming practices used to increase efficiency of energy transfer to increase yields? (give two ways).
- reducing respiratory losses (reducing movement of animals).
- reducing energy loss by simplifying food chains (herbicides and pesticides).
What are decomposers?
Decomposers decompose organic material.
