ecology

• Population


  Group of organisms of the same species living in the same area at the same time
• Species


  Group of organisms with similar characteristics, who can interbreed and produce fertile offspring
• Types of organisms


  • Autotrophs
  • Heterotrophs
• Autotrophs


  Organisms that make their own food. absorb CO2, H2O and inorganic nutrients from abiotic environment and use them to synthesise all the carbon compounds they need
• Heterotrophs


  Organisms that obtain food from other organisms
• Modes of heterotrophic nutrition

  • Saprotrophs
  • Consumers
  • Decomposers
• Saprotrophs


  Obtain organic nutrients from dead organisms by external digestion
• Consumers


  Feed on living organisms by ingestion
• Decomposers


  Fungi and bacteria that obtain organic nutrients from dead material by internal digestion
• Community

  Group of populations of different species living together and interacting with each other in an area
• Ecosystem


  Community forms an ecosystem by its interactions with the abiotic environment
• Nutrient recycling in ecosystems

  1. Energy is supplied to ecosystems in the form of light and converted to chemical energy by producers

  2. Ecosystems have limited supplies of nutrients but these supplies do not run out because nutrients can be recycled
• Trophic levels

  Levels in a food chain where each species feeds on the previous one, with less chemical energy at each successive stage
• Energy pyramids

  Diagrams that show how much energy flows through each trophic level in a community
• Carbon sources

  Autotrophs absorb CO2 either from the atmosphere or from water, and convert it into carbohydrates
• Combustion


  Process that produces CO2 by the breakdown of carbon compounds
• Methane


  Produced naturally by a group of prokaryotes that break down organic matter in anaerobic conditions and release methane as a waste product
• Limestone


  Rock that consists mainly of calcium carbonate, which locks up huge amounts of carbon
• Greenhouse effect


  Certain gases in the atmosphere trap long-wave radiation emitted from the Earth's surface, causing global warming
• Global temperatures and climate patterns are influenced by the concentrations of greenhouse gases in the atmosphere, which are increased by human activities
• Coral reefs and the pH of the ocean drop due to the increase in CO2 concentration, causing ocean acidification which will become more severe if the rise in CO2 concentration continues
• Analyzing trapped air bubbles

  Determine CO2 concentration
• Analyzing ratios of hydrogen isotopes in water molecules

  Deduce temperatures
• CO2 is a greenhouse gas