A
the principal source of energy input to biological systems
What is the sun?
the transfer of energy from one organism to the next, beginning with a producer
What does a food chain show?
network of interconnected food chains
What is a food web?
an organism that makes its own organic nutrients, usually using energy from sunlight, through photosynthesis
What is a producer?
They allow us to see the total energy at a trophic level which is more accurate than the number of individuals
What is the advantage of pyramids of energy over pyramids of number?
the position of an organism in a food chain, food web or ecological pyramid
What is a trophic level?
an animal that gets its energy by eating plants
What is a herbivore?
group of organisms of one species, living in the same area, at the same time
What is a population?
an animal that gets its energy by eating other animals
What is a carnivore?
decomposition, nitrification, nitrogen fixation and denitrification
What are the ROLES of microorganisms in the nitrogen cycle
Energy, Numbers or Biomass
What types of pyramids can we make to represent feeding relationships?
an organism that gets its energy by feeding on other organisms
What is a consumer?
producers, primary consumers, secondary consumers, tertiary consumers and quaternary consumers
What are the names of the different trophic levels in food chains?
an organism that gets its energy from dead or waste organic material
What is a decomposer?
increased availability of nitrate and other
ions
• increased growth of producers
• increased decomposition after death of
producers
• increased aerobic respiration by
decomposers
• reduction in dissolved oxygen
• death of organisms requiring dissolved
oxygen in water
What are the steps of Eutrophication?
the number of different species that live in an area
What is biodiversity?
Through altering food webs and food chains,
How can humans can have a negative impact on habitats?
the enhanced greenhouse effect and climate change
What are the effects of pollution of the air by methane and carbon dioxide?
(a)increased area for housing, crop plant production and livestock production
(b) extraction of natural resources
(c) freshwater and marine pollution
What are reasons for habitat destruction?
• decomposition of plant and animal protein to ammonium ions, nitrification, nitrogen fixation by lightning and bacteria, absorption of nitrate ions, production of amino acids and proteins, feeding and digestion of proteins, deamination, denitrification
What are the steps of the nitrogen cycle?
food supply, competition, predation and disease
What are FACTORS affecting population growth rates?
reducing biodiversity, extinction, loss of soil, flooding and increase of carbon dioxide in the atmosphere
What are the undesirable effects of deforestation as an example of habitat destruction?
(a) agricultural machinery to use larger areas of
land and improve efficiency
(b) chemical fertilisers to improve yields
(c) insecticides to improve quality and yield
(d) herbicides to reduce competition with
weeds
(e) selective breeding to improve production by
crop plants and livestock
How have humans have increased food production?
Because there is energy loss between each trophic level so the amount of energy available becomes too small
why do food chains usually have fewer than five trophic levels?
What are some threats to wildlife?