Bio

• Food chain


  Transfer of energy from one organism to the next, beginning with a producer
• Food web


  Network of interconnected food chains
• Producer


  Organism that makes its own organic nutrients, usually using energy from sunlight, through photosynthesis
• Consumer


  Organism that gets its energy by feeding on other organisms
• Types of consumers

  • Primary
  • Secondary
  • Tertiary
  • Quaternary
• Herbivore


  Animal that gets its energy by eating plants
• Carnivore


  Animal that gets its energy by eating other animals
• Decomposer

  Organism that gets its energy from dead or waste organic material
• Using food chains and food webs to describe the impact humans have

  1. Overharvesting of food species

  2. Introducing foreign species to a habitat
• Trophic level

  The position of an organism in a food chain, food web or ecological pyramid
• Pyramid of energy

  • Advantages over pyramids of biomass over pyramid of number to represent a food chain includes higher accuracy, better idea of quantity at each level.
• Carbon cycle

  1. Photosynthesis

  2. Respiration

  3. Feeding

  4. Decomposition

  5. Formation of fossil fuels

  6. Combustion
• Nitrogen cycle

  1. Decomposition of plant and animal protein to ammonium ions

  2. Nitrification

  3. Nitrogen fixation by lightning and bacteria

  4. Absorption of nitrate ions by plants

  5. Production of amino acids and proteins

  6. Feeding and digestion of proteins

  7. Deamination

  8. Denitrification
• Roles of microorganisms in the nitrogen cycle

  • Decomposition
  • Nitrification
  • Nitrogen fixation
  • Denitrification
• Decomposition of plant and animal protein to ammonium ions

  The first step in the nitrogen cycle, where organic matter such as plant and animal remains are broken down by decomposers, releasing ammonium ions (NH4+) into the soil or water.
• Nitrogen fixation by lightning and bacteria

  The process of converting nitrogen gas (N2) from the air into ammonia (NH3) through the action of lightning strikes or nitrogen-fixing bacteria that live in the soil or on the roots of certain plants.
• Absorption of nitrate ions by plants


  The fourth step in the nitrogen cycle, where plants absorb nitrate ions from the soil through their roots and use them to produce amino acids and proteins, which are essential for their growth and development.
• Feeding and digestion of proteins

  The sixth step in the nitrogen cycle, where animals consume plants or other animals and digest the proteins and amino acids, releasing them back into the environment through waste products.
• Nitrification


  The second step in the nitrogen cycle, where ammonium ions (NH4+) are converted into nitrites (NO2-) and then into nitrates (NO3-) by nitrifying bacteria in the soil or water.
• Deamination


  The seventh step in the nitrogen cycle, where amino acids are converted into ammonia (NH3) through a process called deamination, which can occur in animals when they break down proteins.
• Production of amino acids and proteins

  The fifth step in the nitrogen cycle, where amino acids are produced from nitrogen and used to build proteins, which are essential for the growth and development of plants and animals.
• Denitrification

  The final step in the nitrogen cycle, where denitrifying bacteria convert nitrate (NO3-) back into nitrogen gas (N2), which is released back into the air and helps to maintain the balance of nitrogen in the environment.
• Movement


  An action by an organism or part of an organism causing a change of position or place
• Respiration


  The chemical reactions in cells that break down nutrient molecules and release energy for metabolism
• Sensitivity


  The ability to detect and respond to changes in the internal or external environment
• Growth


  A permanent increase in size and dry mass
• Reproduction


  The processes that make more of the same kind of organism
• Excretion


  The removal of the waste products of metabolism and substances in excess of requirements
• Nutrition


  The taking in of materials for energy, growth and development
• Species


  A group of organisms that can reproduce to produce fertile offspring
• Binomial naming system

  An internationally agreed system in which the scientific name of an organism is made up of two parts showing the genus and species
• Constructing and using dichotomous keys


  Based on identifiable features
• Classification systems


  Aim to reflect evolutionary relationships
• DNA sequences


  Used as a means of classification
• Groups of organisms which share a more recent ancestor

  Have base sequences in DNA that are more similar than those that share only a distant ancestor
• Main features used to place organisms into groups within the animal kingdom

  • The main groups of vertebrates: mammals, birds, reptiles, amphibians, fish
  • The main groups of arthropods: myriapods, insects, arachnids, crustaceans
• Main features used to place all organisms into one of the five kingdoms

  • Animal, plant, fungus, prokaryote, protoctist
• Main features used to place organisms into groups within the plant kingdom

  • Ferns and flowering plants (dicotyledons and monocotyledons)
• Viruses


  Features limited to a protein coat and genetic material
• Cell structures in plant and animal cells

  • Cell wall, cell membrane, nucleus, cytoplasm, chloroplasts, ribosomes, mitochondria, vacuoles