Endogenous pacemakers and exogenous zeitgebers are used to control biological rhythms. Biological rhythms are controlled by environmental factors such as light‚ temperature and food availability; these are known as exogenous (external) zeitgebers. However biological organisms are complex systems‚ where many different processes are taking place. This means that it would be useful to have something which would co-ordinate these processes‚ keeping everything in time – an endogenous pacemaker. This
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Discuss the influence of endogenous pacemaker and exogenous zeitgebers on one or more biological rhythms (24 Marks) Introduction This essay will outline and evaluate the role that endogenous pacemakers (ep’s) or internal clocks have on our biological cycles. It will also consider exogenous zeitgebers (ez’s) or external timekeepers. The two cycles to be considered are circadian and ultradian. AO1 Psychologists believe that the circadian rhythm (sleep/wake) is controlled by an
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Causes of the Wealth of Nations. Some have taken this as indicating that he was concerned primarily with economic growth. In this way‚ Smith moved away from the Cantillon-Physiocratic system which concentrated on "natural equilibrium" of circular flows‚ and brought back into economics what had been the Mercantilists’ pet concern. Smith posited a supply-side driven model of growth. Succinctly we can lay out the story via the simplest of production functions: Y = ｦ(L‚ K‚ T) where Y is output
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Discuss the role of endogenous pacemakers and exogenous zeitgebers in the sleep/wake cycle and one other rhythm (24) Siffre (1975) dedicated 6 months of his life to be spent isolated in an underground cave in Texas. During which‚ he was exposed to only artificial light‚ and was given no natural exogenous zeitgebers. This meant that his biological rhythms were subject to free running‚ whereby the body has to dictate its own resources and has no external aid‚ such as natural light or social norms
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ENDOGENOUS PROCESSES AND ASSOCIATED LANDFORMS THE EVER CHANGING LANDSCAPE • • • • • • Earth’s surface is ever changing Endogenous processess- interior of the earth Mountains‚ plateaus and plains formed Occurences of volcanoes and earthquakes Processess- slow and sudden Many areas rise or subside NOTABLE CHANGES • • • • Breaking of Gondwanaland 120 mya Indian peninsula started drifting towards north Took present shape around 40 mya Raising of Himalayas- present height during last 1 million years
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made public his theory on population dynamics and its relationship with the availability of resources. The essay was the result of his skepticism towards positivist theorists‚ praising the perfectibility of man and greeting the advances and diffusion of human knowledge as a source of welfare and freedom for future generations. Disagreeing with such perspectives‚ Malthus maintained that the development of mankind was severely limited by the pressure that population growth exerted on the
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Growth Mindset The growth mindset theory says that the abilities you already have can be expanded with dedication. You can improve your intelligence just by working hard and knowing that your brain is capable of constantly learning new things. Anyone can teach themselves this mindset‚ I personally feel like I have because math has never come easily to me but I have never been closed minded about it and I always try my best to understand it. Even though math is not easy for me I still manage to understand
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1. Neoclassical Theory Causes of Economic Growth a. Increase in labor quantity (population growth) b. Improvement of labour through training and education c. Increase in capital (higher savings and investments) d. Improvements in technology Neoclassicals believe that government control inhibits growth as it encourages corruption‚ inefficiency and offers no profit motive for entrepreneurship. Underdevelopment is seen as the result of government inefficient use of resources and state intervention
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Endogenous Pacemakers‚ Exogenous Zeitgebers Essay Plan 1. Describe in detail endogenous pacemakers- suprachiasmatic nucleus (SCN) in the hypothalamus‚ SCN obtains information about light from the eye via the optic nerve‚ happens even when eyes are shut‚ as light penetrates the eyelids. If endogenous clock is running slowly‚ morning light automatically shifts the clock ahead‚ making the rhythm correct with the world outside again. SCN- pair of structures- one in each hemisphere of the brain‚ and
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hours)‚ which is therefore able to control the circadian rhythm. As the biological body clock is controlled inside it is known as endogenous‚ these are called endogenous pacemakers. So how do these work on their own to affect the sleep-wake cycle and why do we need external factors to also help control our circadian rhythms? There have been many studies into endogenous pacemakers to see if our sleep-wake cycle (circadian rhythms) will still last 24hours without any exogenous zeitgebers(external
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