bio chp#05

• Living organisms


  Have the capacity to respond to changes in the environment
• Response of the organism

  Adaptive - enhances the probability of an organism to survive and reproduce
• Behaviour


  The response of an organism to stimuli
• Behaviour of an organism is usually inherited but can be modified by experience
• Behaviour


  All those responses to stimuli involved in the integrated functioning of the entire organism
• Stimuli


  A detectable change (physical or chemical) in the environment that causes an organism to respond
• Interpretation and response to stimuli

  1. Receptors send signals through nerve cells to CNS

  2. CNS interprets signals based on stimuli

  3. Organism responds or ignores
• Positive response


  Organism wants more or is attracted to the stimulus
• Negative response


  Organism wants to avoid the stimulus
• Ignored reaction


  Organism decides to ignore the stimulus
• Genes


  • Control the development of physiological systems like the nervous system
  • Produce proteins important for behavioural responses
• Genetic basis of behaviour can be demonstrated through experimental methods like inbreeding and artificial selection
• Biological rhythms


  Cyclic physiological patterns of activities in an organism in response to periodic environmental changes
• Biological clock


  Internal mechanism that controls physiological activities independently of external stimuli
• Types of animals based on activity patterns

  • Diurnal (active during day)
  • Nocturnal (active at night)
  • Crepuscular (active at dawn/dusk)
• Innate behaviour


  Behaviour performed in response to stimulus at the time of birth without prior experience
• Orientation behaviours


  Behaviours where an organism moves or changes direction in response to a stimulus source
• Taxis


  Directional movement toward or away from a particular stimulus
• Positive taxis


  Movement toward the stimulus
• Negative taxis


  Movement away from the stimulus
• Kinesis


  Non-orientation movement where the animal alters its rate of movement according to stimulus intensity
• Reflex


  Rapid automatic response of the body or part of the body to simple stimuli
• Instinct/Instinctive behaviour


  Inherited behaviour pattern that does not require learning or practice
• Instinctive behaviours


  • Migration of salmon fish
  • Dances of bees
  • Nest building by birds
  • Building of spider's orb web
• Waggle dance


  Indicates the distance of food source from the hive
• Round dance


  Indicates the direction of food source from the hive
• Bees can communicate about food up to 2 kilometers away
• Instinct or inborn behaviour


  Bees are born with the ability to understand this type of behaviour
• Nest building by birds

  • All birds have different strategies to build nests for their eggs deposition
  • Long tailed tailor-birds have ability to build a hanging nest
• Nest building by young long tailed tailor-bird


  1. Builds nest between hanging leaves with twigs and grass

  2. Has no prior experience in nest building

  3. Builds nest by instinct behaviour
• Spider's orb web


  • Built of silk threads secreted by special silk glands
  • Spider applies a set of sub rules for measuring angles and walking set distances up certain threads
  • Follows a program of elementary rules to build a complex structure without a plan
• Instinct or inborn behaviour

  Spider's orb web is the outcome of highly complex and instinct or inborn behaviour patterns
• Courtship behaviour of stickleback fish

  • Sexually mature male develops a bright throat and red belly
  • Territorial male builds nest and becomes aggressive to protect from other males
  • Female approaches male's territory, male leads female to nest and stimulates spawning
  • Male stays close to nest to look after offspring
• Instinct or inborn behaviour

  Stickleback fish's mating behaviour is instinct or inborn without prior experience
• Learning behaviour


  Animals modify their behaviour as a result of specific experience, allowing them to change and improve their responses
• Innate behaviour


  Inherited, reflex action, permanent, contributes to survival, common in short-lived animals, no adaptation time required
• Learning behaviour


  Acquired through knowledge/experience, can be modified, improves behavioural traits, common in long-lived animals, adaptation time required
• Habituation


  Animals learn to ignore repeated, irrelevant stimuli, occurs at the brain level, the stimulus is still perceived but the animal decides to no longer pay attention
• Habituation


  • Wild squirrel losing fear of humans over repeated, harmless interactions
• Imprinting


  Young animal fixes attention on first moving object or animal after birth/hatching, information is firmly fixed and used later in life