Biology Grade 12 unit 5 Part 1

Biology Grade 12 Part one Unit 5 Behavior Main content 5.1 An introduction to behaviour 5.2 Innate behaviour 5.3 Learned behaviour 5.4 Examples of behaviour patterns Definitions Of Behaviour The observable response a person makes to any situation. A manner of acting or conducting yourself. The way a person behaves towards other people. The actions or reactions of a person or animal in response to external or internal stimuli. The responses or reactions or movements made by an organism in any situationfrom a biological viewpoint The co-ordinated response of an organism to an internal or external stimulus. components of co-ordinated response: a receptor of some kind to detect the stimulus an effector of some kind to produce the response, and linking system or coordinating system Central nervous System(CNS) Hormonal system(HS) plants response to unidirectional stimuli? phototropism The response(behavior) of plant towards light is called phototropism. Plant shoots are positively phototropic because they grow towards light. Plants roots are negatively phototropic because the grow away from the light Auxins The response is co-ordinated by plant growth hormone called auxins. The auxins are produced in the shoot tip The auxins stimulate the shoot cells to divide and enlarge, Plant growth is greatest on the side away from the light. it causes the shoot to bend towards the light. simple animals response to stimuli? Two different types of responses in simple organisms Taxes (singular taxis) Kineses (singular kinesis) Taxes (singular taxis) the animal moves along a gradient of intensity of a stimulus towards the greatest intensity of the stimulus (a positive taxis) away from the greatest intensity (a negative taxis); there is a directional response to a directional stimulus. Kineses (singular kinesis) a change in the intensity of the stimulus brings about a change in the rate of movement, not a change in the direction of movement.