ecology (5th Yr)

• biosphere


  the part of the earth inhabited by living organisms including land ocean and the atmosphere in which life can exist. It is the global ecosystem
• ecology


  Scientific study of interactions of living things and their environment
• organism


  a living thing that carries out the characteristics of life
• species


  a group of similar organisms capable of interbreeding and producing fertile offspring
• population


  All the members of one species in a particular area
• community


  All the different populations that live together in an area
• ecosystem


  a community of living organisms that interact with each other and their environment within a particular area
• environment


  all the condition in which the organism lives which affect the growth and development of the organism example grassland
• habitat


  place in an environment where an organism lives
• niche


  the role of an organism in an ecosystem
• biotic


  living factors in the environment
• abiotic


  Non-living factors in an ecosystem
• climatic factors


  average weather conditions that affect the community in an ecosystem
• Edaphic factors


  Factors relating to the soil
• energy flow


  pathway of energy transfer from one organism to the next in an ecosystem due to feeding example along a food chain
• detritus food chain


  a food chain that begins with dead organic matter and animal waste example dead leaves -> woodlouse -> blackbird
• grazing food chain


  a food chain that begins with photosynthesis
• trophic level


  the position of an organism in a food chain
• pollution


  any human addition (contamination) to a habitat or the environment that leaves it less able to sustain life
• pollutant


  chemicals of human origin that harm the environment
• eutrophication


  a condition where lakes become over enriched with nutrients resulting from excess artificial fertilisers washed into rivers and lakes
• What are trophic levels?

  Trophic levels are the feeding positions in a food chain or food web.
• What do trophic levels represent in terms of energy transfer?

  Trophic levels represent the stages of energy transfer from one organism to another.
• What is an example of a first trophic level organism in an Irish ecosystem?

  Plants, such as grass, are at the first trophic level.
• How can trophic levels be simplified for better understanding?

  - Trophic levels are like steps in a food ladder. - Each step represents a group of organisms that eat in a similar way. - Example: Grass (1st level) → Rabbit (2nd level) → Fox (3rd level).
• Why are ecological pyramids typically wider at the bottom and narrower at the top?

  Because there are usually more producers than consumers, and energy is lost as it moves up the trophic levels.
• What does a pyramid of numbers show?

  A pyramid of numbers shows the count of individual organisms at each trophic level.
• What is the 10% rule in energy transfer?

  The 10% rule states that only about 10% of the energy from one trophic level is transferred to the next.
• Why is there decreasing available energy at higher trophic levels?

  This results in less energy available at higher trophic levels, limiting the number of trophic levels in an ecosystem.
• ecological niche of an organism is its functional role in the community
• competition is the struggle between organisms for limited resources or resources that are in short supply
• intraspecific competition is the struggle for limited resources between organisms belonging to the same species
• interspecific competition is the struggle for limited resources between members of different species
• scramble competition is the struggle for limited resources whereby each organism gets some of the resource
• in contest competition there is direct conflict for limited resources between two individuals whereby only one is successful in gaining the resource - the winner takes all
• an adaptation is any change in the structure or behaviour of an organism that makes it better suited to its environment and avoid competition
• organisms live in populations because they are:

  • suitable conditions
  • safety in numbers
  • breeding purposes