Taxes and kineses

• Taxis


  A simple, directional response to a stimulus where the direction of the stimulus determines the direction of the response
• Taxes

  • Single-celled algae/protoctista move towards light (phototaxis)
  • Earthworms move away from light (Negative phototaxis)
  • Male insects fly towards chemicals secreted by mature females (Positive chemotaxis)
  • Daphnia move towards a high concentration of oxygen (Positive aerotaxis)
• Kinesis results in an increase in random movement
• Survival and Response in Simple Organisms-Taxes and Kineses

  • Simple innate forms of behaviour relying on simple reflex actions in simple organisms, allowing mobile organisms to respond to environmental changes and maintain favorable conditions for survival
• Taxes and Kineses


  • Genetically determined behaviors that cannot be adapted or modified, showing a stereotyped pattern in all members of a species, typical of simple organisms with a short life cycle
• Advantages of Taxes

  • Need light for photosynthesis, to make organic compounds. Increases survival chances
  • Better able to conserve water, find food & avoid predators
  • Increases chance of finding a mate of the same species
  • Oxygen is used in respiration
• Kinesis


  A non-directional response to a stimulus where the rate of movement or change of direction is related to the intensity of the stimulus, resulting in an increase in random movement