Energetics Flashcards
State 3 basic functions of an organism.
Assimilation- acquiring energy and materials from the environment for growth.
Reproduction- part of the energy and materials must be used to produce new individuals.
Ability to respond to external stimuli- adapt to biotic and abiotic factors.
What is an autotroph?
An organism that derives its energy from the sun or chemicals. They use photosynthetic or chemosynthetic processes to synthesise organic molecules.
What is a heterotroph?
They derive their energy and carbon source from other organic molecules. Herbivores, carnivores and decomposers are all heterotrophs.
State 4 trophic levels.
producers,
primary consumers,
secondary consumers,
tertiary consumers.
What percentage of the suns energy is converted by producers?
1.2%.
State 4 inefficiencies in energy conversion between trophic levels.
Limited consumption,
Limited assimilation,
Respiration,
Heat production.
What are ecological pyramids?
A way of quantitatively representing food chains, using figures relating to energy, population numbers or biomass.
What is a food web?
A way of summarising feeding relationships in communities by looking at populations.
What is a trophic cascade?
When a change in one level has effects further up/ down the food chain. These changes can be direct or indirect.
Describe ‘top-down’ control of a food web.
When a predator determines the presence of herbivores and therefore plants in a food web. A dominant member of a food web is a keystone species.
State 3 benefits of species diversity.
More habitats,
More food resources,
More resilience in the face of climate change.
