ecosystems

• Ecosystems consist of communities of interdependent organisms and abiotic components of the environment; matter and energy flow through these systems
• Ecosystems


  • Consist of different communities and populations of different species
  • Name and describe the different relationships within and between these groups
• Species


  Each living thing belongs to a species
• Population


  Consists of others of the same species in the same area at a particular time
• Community


  Consists of different populations living together in the same place
• Ecosystem


  Consists of communities of organisms living and interacting together and their non-living environment
• Components of an ecosystem

  • Biotic (living parts)
  • Abiotic (non-living parts)
• Producers


  • Form the base of the food chain
  • Plants are producers, using chlorophyll to capture light energy and convert carbon dioxide and water into glucose
  • Known as autotrophs (self-feeders)
  • Produce oxygen which is essential for aerobic respiration in majority of organisms
• Consumers


  • Herbivores (primary consumers that eat plants)
  • Carnivores (secondary or tertiary consumers that eat other animals)
  • Omnivores (eat both plants and animals)
  • Detritivores (eat tissue of dead or decaying organisms or waste from other animals)
• Decomposers


  Convert organic matter into simple inorganic materials, helping to recycle matter within ecosystems so as to remain sustainable
• Decomposers


  • Fungi and bacteria
• Ecological Niche


  Each species has a specific role in the ecosystem, including habitat, nutrition, and relationships
• Predator-Prey


  One species (predator) kills and eats another species (prey)
• Competition


  Occurs due to overlapping needs for the same resource, can be interspecific (between different species) or intraspecific (within the same species)
• Symbiotic Relationship


  A close ongoing relationship between two organisms of different species, where at least one organism benefits
• Types of Symbiotic Relationships

  • Parasitism
  • Mutualism
  • Commensalism
• Herbivore-Plant Relationship


  Plants develop defences (physical or chemical) against herbivores
• Sampling Methods


  • Quadrats (to estimate distribution and abundance of stationary organisms)
  • Transects (to sample along an environmental gradient)
  • Capture-Mark-Release-Recapture (to determine abundance of mobile animals)
• Plant Structures


  • Roots (anchor plants, obtain oxygen, water and mineral salts)
  • Stems (facilitate movement of liquids, contain vascular bundles)
  • Leaves (contain chlorophyll for photosynthesis, have stomata for gas exchange)
  • Flowers (enable pollination and fertilization)
• Photosynthesis


  Plants use chlorophyll to capture light energy and convert carbon dioxide and water into glucose
• Chlorophyll


  Green pigment in plant cells that is involved in capturing and absorbing light energy
• Being green is not essential to be able to photosynthesise, some plants like algae and phytoplankton may contain other light-capturing pigments
• Cellular Respiration


  Series of chemical reactions in cells that transforms the chemical energy in food into adenosine triphosphate (ATP)
• Aerobic Respiration


  Stage 1 (glycolysis) occurs in the cytosol without oxygen, Stage 2 and 3 occur in the mitochondrion and require oxygen
• Cells with higher energy demands will have more mitochondria, as most of the ATP required is produced in the mitochondrion
• Anaerobic Respiration


  Muscles can respire for a short time without oxygen, producing less energy but at a faster rate