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42 Cards in this Set
- Front
- Back
Define species |
species: a group of organisms that can interbreed and produce fertile offspring |
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Define habitat
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the environment in which a species normally lives or the location of a living organism |
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Define population
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a group of organisms of the same species who live in the same area at the same time |
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Define community |
a group of populations living and interacting with each other in an area |
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Define ecosystem |
a community and its abiotic environment |
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Define ecology |
The study of relationships between living organisms and between organisms and their environment |
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Define autotroph |
an organism that makes its organic molecules from simple inorganic substances |
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Define heterotroph |
an organism that obtains organic molecules from other organisms |
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Define consumer |
an organism that eats other organic matter that is living or recently dead. |
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Define detrivore |
an organism that ingests non-living organic matter |
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Define saprotroph
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an organism that lives on or in non-living organic matter, secreting digestive enzymes into it and absorbing the products of digestion |
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Define trophic level
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The level at which and organism feeds in a food chain (e.g producers - trophic level 1) |
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What is the initial energy source for almost all communities?
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Sun light is the initial energy source for almost all communities. |
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What is meant by food chain?
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A feeding relationship between carnivores, herbivores and producers. |
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What is meant by food web?
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is formed of interconnected food chains |
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What can recycle nutrients?
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Saprotrophic bacteria and fungi (decomposers) |
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Why are energy transfers never 100% efficient?
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Energy is always lost between one trophic level and the next. The energy is: used (respiration), not absorbed (not digested and passed through the faeces), not consumed - not all organisms at each trophic level are eaten. |
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What unit is used for pyramids of energy?
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kJ m^-2 yr^-1
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What is the main reason for the increase in atmospheric carbon dioxide levels?
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The burning of fossil fuels
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What are the five greenhouse gases?
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Carbon dioxide, |
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What is the precautionary principle?
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If the effects of human-induced activity would be very large, perhaps catastrophic, those responsible for the change must prove that it will do NO harm before proceeding. |
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What are the consequences of global temperature rise on arctic ecosystems?
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- Loss of habitats and extensive flooding |
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Which factors increase population size?
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Natality and immigration
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Which factors decrease population size?
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Mortality and emigration |
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What is the sigmoid curve and what are the three phases represented in it?
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It demonstrate population growth. The three phases are: |
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Explain the exponential growth phase
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During exponential growth, there are no great limitations on growth. The rate of natality and immigration exceeds the rate of mortality and emigration. There are adequate nutrients and little waste has accumulated. |
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Explain the transitional phase. |
The natality rate has started to fall but still exceeds the mortality and emigration rate. Less resources become a limiting factor. |
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Explain the plateau phase.
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The rate of natality and immigration is equal to the rate of mortality and emigration. The supply of nutrients and level of waste do not support growth.
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List three limiting factors on population increase.
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1) competition for resources
2) level of predation 3) disease/parasites |
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List the hierarchy of taxa (from largest to smallest)
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Kingdom, phylum, class, order, family, genus, species |
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Give an example of hierarchy of taxa
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Animalia, chordata, mammalia, primates, homindae, homo, sapiens |
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What are the two latin names given in the binomial system?
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The genus + species |
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What are the structural features of bryophyta (mosses and liveworts)?
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- No roots or cuticles |
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What are the structural features of filicinophyta (ferns)?
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- they have roots and cuticles |
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What are the structural features of coniferophyta (conifers e.g. christmas trees)?
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- can be shrubs to very large trees |
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What are the structural features of angiospermophyta (flowering plants)?
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- can be herbaceous plants, shrubs or trees |
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What are the structural features of porifera (sponges)?
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- no specific body shape, |
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What are the structural features of cnideria (jelly fish and sea anemones)?
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- bilaterally symmetric |
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What are the structural features of Platyminthes? NB/ think platworms/flatworms
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-flat and unsegmented body
-bilaterally symmetric -one entrance to gut |
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What are the structural features of Annelida (segmented worms)?
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-segmented body |
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What are the structural features of Mollusca (snails, slugs and squids)?
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-soft, flexible boyd with no obvious segmentation, |
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What are the structural features of Anthropoda (crabs, spiders, scorpions, insects and centipedes)?
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-segmented body |