Energy and Ecosystems Flashcards
What 2 sources of carbon dioxide do plants use?
Aquatic and atmospheric
Why are energy transfers never 100% efficient?
Energy is transferred to surroundings as heat (via respiration).
In which two ways can biomass be measured?
Mass of carbon or dry mass of tissue per given area.
What can calorimetry be used to measure?
The amount of chemical energy stored in dry biomass.
What is the definition of gross primary production?
The chemical energy store in plant biomass, in a given area or volume.
What is the equation used to calculate net primary production?
NPP = GPP - R
Gross primary production - respiration.
What is the definition of net primary production?
The chemical energy store in plant biomass after respiratory losses to the environment has been taken into account.
What is the unit for NPP, GPP and R?
Biomass in a given area and time (kJ ha-1 year-1)
Which farming practices can increase food efficiency in food chains?
Farming animals: reduce respiratory losses by reducing movement and heating enclosures.
Farming plants: simplify food webs by removing weeds and using pesticides.
An ecosystem in a particular area includes:
Living components - biotic factors;
Non-living components - abiotic factors (temperature and rainfall, etc).
All ecosystems include and depend on…
Primary producers.
Primary producers are organisms that make their own glucose.
In ecosystems where water and sunlight are available, the process of photosynthesis enables plants to…
Synthesises of organic compounds from carbon dioxide.
In terrestrial (land-based) ecosystems, plants use CO2 from the…
Atmosphere.
In aquatic (water-based ecosystems), plants use CO2 …
Dissolved in water.
The process of photosynthesis transforms light energy into chemical energy held in biological molecules. The chemical energy in these biological molecules can then be used by other organisms within the community known as consumers.
Primary consumers - feed on producers.
Secondary consumers - feed on primary consumers.
Tertiary consumers - feed on secondary consumers.
Most of the sugar synthesised by plants are used by the plant as…
Respiratory substrates - a molecule that can be used in respiration, to release energy for growth.
The biomass of an organism is:
Mass of living material of the organism or tissue.
The chemical energy that is stored within the organism or tissue.
What are 3 examples of biological molecules that contain nitrogen?
Amino acids, proteins, nucleic acids.
Which forms of inorganic molecules and ions, containing nitrogen, are found in biological systems and the physical environment?
Atmospheric nitrogen gas (N2), ammonium ions, nitrates, nitrites.
What are the main processes that recycle nitrogen in the environment?
Feeding, digestion, excretion, death, decomposition, nitrogen fixation (by bacteria, plants, and lightning).
Which are the microbial processes of recycling nitrogen in the environment?
Nitrogen fixation, nitrification, dentirification, ammonification.
