IB ESS Topic 2, Questions and answers, 100% Accurate, graded A+

IB ESS Topic 2, Questions and answers, 100% Accurate, graded A+ Biotic factors - -the living organisms in an ecosystem abiotic factors - -the non-living factors in an ecosystem trophic level - -the position an organism occupies in a food chain as a result of its feeding habits food chain - -a simple linear relationship which shows how energy is transferred between organisms as each consumes an organism from a lower trophic level food web - -a group of interconnected food chains biomass - -the mass of organic material in an organism or ecosystem producers - -convert light energy and water, CO2 and minerals into new materials consumers - -cannot make their own food and much eat other organisms to obtain energy Ecological pyramids - -allow you to examine easily energy transfers and losses. they give an idea of what feeds on what and what organisms exist at the different trophic levels. they also help demonstrate that ecosystems are unified systems, and they are in balance pyramid of numbers - -represents the number of organisms at each trophic level pyramid of biomass - -represents the standing stock of each trophic level pyramid of productivity - -represents the flow of energy through a trophic level species - -a particular type of organism that can be interbreed and produce fertile offspring population - -a group of one species living in a given area at the same time habitat - -the environment where a species normally lives niche - -how an organism makes a living community - -a group of populations in a given area ecosystem - -a community of interdependent organisms and the abiotic environment in which they live competition - -any time there are limited resources the organisms much compete for them parasitism - -one organism lives in or on the other host gaining food from it ex: nematodes mutualism - -both organisms benefit and none suffer ex: lichen predation - -when one animal eats another ex: felius catus eating field mouse herbivory - -an animal eating a plant ex: white tailed deer eating oak leaves System - -assemblage of parts and the relationships between them which enable them to work together Open system - -Exchanges matter and energy Closed system - -Exchanges energy but not matter Isolated system - -Exchanges neither matter nor energy 1st law of thermodynamics - -Energy cannot be created nor destroyed 2nd law of thermodynamics - -Entropy of a system will increase over time Entropy - -The measure of the evenness of energy distribution in a system Equilibrium - -A state if balance which exists between the different parts of any system Steady state equilibrium (dynamic) - -Constantly changing to maintain equilibrium Static equilibrium - -No change over time (non living ) Stable equilibrium - -The system tends to return the same equilibrium after a disturbance Unstable equilibrium - -The system returns to a new equilibrium after a disturbance Negative feedback - -Works to counteract any deviation from the stable state of equilibrium Positive feedback - -Enhances the change in the system