\n<\/p>\n
Reproduction, human growth and development, human populations<\/strong><\/p>\n The linking of a number of simple reflexes to produce a more complex pattern of behaviour as shown by the reflexes involved in the feeding of a new-born human infant.<\/p>\n<\/td>\n<\/tr>\n Classical conditioning, illustrated by the work of Pavlov on the control of salivation in dogs.<\/p>\n Operant conditioning, illustrated by the work of Skinner on rats.<\/p>\n The importance of reinforcement stimuli and rewards in learning .<\/p>\n Candidates should be able to explain examples of behaviour in terms of classical conditioning and of operant conditioning and to evaluate parallels between animal and human behaviour.<\/p>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n Sign stimuli and innate releaser mechanisms as components in simple courtship patterns.<\/p>\n The role of hormones and pheromones in courtship behaviour.<\/p>\n Candidates should be able to analyse individual components in simple courtship patterns, and evaluate comparisons between the behaviour of humans and other animals.<\/p>\n<\/td>\n<\/tr>\n The effect of oestrogen and progesterone on the uterine<\/p>\n endometrium.<\/p>\n The role of negative feedback in regulating hormone concentrations.<\/p>\n<\/td>\n<\/tr>\n Candidates should be able to evaluate the different methods of birth control.<\/p>\n<\/td>\n<\/tr>\n The key stages in in vitro fertilisation:<\/p>\n progesterone in controlling the events of pregnancy.<\/p>\n Confirmation of pregnancy by determining HCG and progesterone levels.<\/p>\n<\/td>\n<\/tr>\n mother<\/p>\n \u00a0<\/p>\n<\/td>\n Candidates should be able to represent graphically and interpret data relating to growth and growth rate.<\/p>\n<\/td>\n<\/tr>\n Puberty and the principal physical changes associated with it. The evolutionary importance of a long pre-puberty stage in the human lifespan.<\/p>\n<\/td>\n<\/tr>\n Candidates should be able to:<\/p>\n Transmission of pathogens by droplet infection and contact, or in food and water.<\/p>\n Natural immunity as production of antibodies in response to antigens. Immunological memory. (Details of the mechanisms of the immune response not required.)<\/p>\n Artificial immunity by vaccination. The limitations of vaccination related to variability of antigens in pathogens.<\/p>\n The herd immunity effect.<\/p>\n Candidates should be able to:<\/p>\n The relationships between diet, exercise and cardiovascular disease. Atheroma formation, formation of blood clots, aneurysm, myocardial infarction and cerebrovascular accident.<\/p>\n The relationships between air pollution and smoking and chronic bronchitis, emphysema and lung cancer. The development and effects on lung function of bronchitis, emphysema and lung cancer.<\/p>\n The relationship between ultra-violet light and malignant skin tumors. Tumor growth and metastasis.<\/p>\n Candidates should be able to explain the biological effects of the disorders listed, and to evaluate measures that might be taken to reduce the risk factors.<\/p>\n<\/td>\n<\/tr>\n Candidates should be able to:<\/p>\n suggest the most appropriate technique to use in the diagnosis or screening of a particular condition;<\/p>\n evaluate the issues arising from the use of screening programmes for inherited conditions.<\/p>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n Behaviour is what an animal does and how it does it. To some extent all behaviour has a genetic basis but in general, behaviour is a response to some environmental stimulus. Ethology is the correct term for the study of behaviour in its natural habitat. It is mostly a descriptive science.<\/p>\n There are two types of behaviour innate and learned.<\/p>\n Some behaviours are a blend of both so classification is not always so easy<\/p>\n \u00a0<\/p>\n<\/td>\n<\/tr>\n Types of innate behaviour:<\/strong><\/p>\n 1. Kinesis: \u201cchange the speed of random movement in response to environmental stimulus\u201d \u00a0<\/p>\n<\/td>\n<\/tr>\n Reflexes can be linked together to produce more complicated behaviours. The example of this that you have to learn is breast-feeding in humans.<\/p>\n There are several reflexes involved in the sequence.<\/p>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n The reflex that empties the bladder is as follows. The full bladder is the stimulus which causes the sphincter muscles around the base of the urethra to relax, these muscles are connected to the autonomic nervous system \u2013 to modify it this muscular relaxation has to be prevented.<\/p>\n Learned behaviours develop during an animals lifetime and are not passed on genetically to its offspring. They vary from very simple to the complex social interactions in primates and whales. Since learned behaviours are not \u201chardwired\u201d they can often be adapted \u2013 this adaptation of behaviour forms the basis of animal training.<\/p>\n When a reflex is modified it is because the stimulus that causes the reflex also causes sensory information to be sent to the brain. When the learning has occurred this information causes inhibitory signals to be sent from the CNS preventing the normal reflex response<\/p>\n \u00a0<\/p>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n \u00a0<\/p>\n<\/td>\n<\/tr>\n Young geese (goslings) do not immediately recognise their mother but they imprint<\/strong> on her. There is a sensitive period during the first few days of a goslings life in which it will follow and become attached to any large object, of course in nature this is the mother but in some experiments it has been humans or even a red watering can. When goslings are distressed they will run to whatever object they have imprinted on which usually will be advantageous as it would be their mother but not so helpful if the object was the red watering can.<\/p>\n It breeding programs to replenish rare or endangered animals care is taken to avoid imprint onto humans and habituation to the presence of humans. In fact habituation to human presence is one of the factors that makes zoo and captive bred animals very different to their wild counterparts and is an obstacle to reintroduction.<\/p>\n \u00a0<\/p>\n<\/td>\n<\/tr>\n Habituation is a reduction in a previously displayed response when a stimulus is repeatedly applied with no reward or punishment following.<\/p>\n If you make an unusual sound in the presence of the family dog, it will respond \u2013 usually by turning its head toward the sound. If the stimulus is given repeatedly and nothing either pleasant or unpleasant happens to the dog, it will soon cease to respond. This lack of response is not a result of fatigue or sensory adaptation and is long-lasting; when fully habituated, the dog will not respond to the stimulus even though weeks or months have elapsed since it was last presented.<\/p>\n \u00a0<\/p>\n<\/td>\n<\/tr>\n If newly-hatched geese are exposed to a moving object of reasonable size and emitting reasonable sounds, they will begin to follow it just as they would normally follow their mother.<\/p>\n This is called imprinting.<\/p>\n The time of exposure is quite critical. A few days after hatching, imprinting no longer occurs. Prior to this time, though, the results can be quite remarkable. A gosling imprinted to a moving box or clucking person will try to follow this object for the rest of its life. In fact, when the gosling reaches sexual maturity, it will make the imprinted object \u2013 rather than a member of its own species \u2013 the goal of its sexual drive.<\/p>\n Much of our knowledge of imprinting was learned from the research of Konrad Lorenz<\/p>\n \u00a0<\/p>\n<\/td>\n<\/tr>\n The conditioned response is probably the simplest form of learned behaviour. It is a response that \u2013 as a result of experience \u2013 comes to be caused by a stimulus different from the one that originally triggered it. The Russian physiologist Ivan Pavlov found that placing meat powder in a dog\u2019s mouth would cause it to salivate.<\/p>\n This unconditioned stimulus<\/strong> (US<\/strong>) is probably a simple inborn reflex involving taste receptors, sensory neurons, networks of interneurons in the brain, and motor neurons running to the salivary glands.<\/p>\n Pavlov found that if he rang a bell every time he put the meat powder in the dog\u2019s mouth, the dog eventually salivated upon hearing the bell alone. This is the conditioned response<\/strong>.<\/p>\n The dog has learned to respond to a substitute stimulus, the conditioned stimulus<\/strong> (CS<\/strong>).<\/p>\n We assume that the physiological basis of the conditioned response is the transfer, by appropriate neurons, of nervous activity in the auditory areas of the brain to the motor neurons controlling salivation. This involves the development of new circuits, which \u2013 we may also assume \u2013 is characteristic of all forms of learning.<\/p>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n Humans may have pheromones<\/strong><\/p>\n It has long been noticed that women living close together (e.g., college roommates) develop synchronous menstrual cycles.<\/p>\n This is thought to be because they release two (as yet uncharacterised) primer pheromones<\/strong><\/p>\n Both pheromones are released from the armpits.<\/p>\n The pheromones are not detected consciously as odours, but presumably trigger the hormonal changes that mediate the menstrual cycle.<\/p>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n Courtship Behaviour:<\/strong><\/p>\n In birds courtship behaviours can include action such as:<\/strong><\/p>\n Aggressive encounters between individuals of the same species<\/b><\/p>\n Why not just fight?<\/b><\/p>\n Do they ever fight?\u2026.Yes\u2026When<\/strong><\/p>\n \u00a0<\/p>\n<\/td>\n<\/tr>\n Monogamous: Male and female form exclusive bond, may be for one breeding season or for life.<\/p>\n Polygamous: Animals have several mates at the same time ~ 2 classes:<\/p>\n \u00a0<\/p>\n<\/td>\n<\/tr>\n Ovarian Hormones<\/strong> \u2013 released from the ovaries (the examiners usually think of oestrogen as been released from the follicle and progesterone as been released from the corpus luteum \u2013 however there is actually some overlap)<\/p>\n These diagrams of human gametes illustrate the differences between male and female.<\/strong><\/p>\n Fertilisation is the fusion of two gametes to form a zygote. \u00a0In humans this takes place near the top of the oviduct<\/u>. Hundreds of sperm reach the egg and use their tails to swim through the follicle cells<\/u> (shown in this photo). When they reach the jelly coat surrounding the ovum they bind to receptors and this stimulates the rupture of the acrosome membrane<\/u> in the sperms, releasing digestive enzymes, which make a path through the jelly coat. When a sperm reaches the ovum cell the two membranes fuse and the sperm nucleus enters the cytoplasm of the ovum. This triggers a series of reactions in the ovum that cause the jelly coat to thicken and harden, preventing any other sperm from entering the ovum. The sperm and egg nuclei then fuse, forming a diploid zygote.<\/p>\n \u00a0<\/p>\n<\/td>\n<\/tr>\n For fertilization to occur, sperm must be deposited in the vagina within a few days before or a day or two after ovulation. Sperm transfer is accomplished by copulation.<\/p>\n Semen is a fluid containing the sperm and liquid added by the seminal vesicles, Cowper\u2019s glands, and the prostate gland. These fluids provide a source of energy (fructose) and perhaps in other ways provide an optimum chemical environment for the sperm. The semen passes through the urethra and is expelled into the vagina.<\/p>\n Once deposited within the vagina, the sperm proceed on their journey into and through the uterus and on up into the fallopian tubes. It is here that fertilization may occur if an \u201cegg\u201d is present (strictly speaking, it is still a secondary oocyte until after completion of meiosis II).<\/p>\n Although sperm can swim several millimetres each second, their trip to and through the fallopian tubes may be assisted by muscular contraction of the walls of the uterus and the tubes. There is some evidence that the egg may release a chemical attractant for sperm. In any case, sperm may reach the egg within 15 minutes of ejaculation. The trip is massive for the sperm and many don\u2019t make it. An average human ejaculate contains several hundred million sperm but only a few hundred reach the egg. And of these, only one will succeed in entering the egg and fertilizing it.<\/p>\n Before sperm can fertilise an egg a process called capacitation must take place. This is where a coating surrounding the sperm is removed it occurs over a period of a few hours and is triggered by the conditions within the female reproductive tract. Once capacitation has occured the acrosome is capable of releasing its enzymes.<\/p>\n Fertilization begins with the binding of a sperm cell to the outer coating of the egg (called the zona pellucida). Enzymes released by the acrosome at the tip of the sperm head digest a path through the zona and enable the sperm to enter the cytoplasm of the egg.<\/p>\n Once a single sperm has penetrated, the cell membrane of the egg calcium ions move into the egg cell. This causes exocytosis of cortical granules from the egg. The granules fuse with the zona pellucida, forming a fertilisation membrane. This prevents the entry of other sperm. The other sperm die within 48 hours. Thus the cortical reaction ensures that only one sperm fertilizes the egg.<\/p>\n Soon the head of the successful sperm enlarges. At the same time, the egg (secondary oocyte) completes meiosis II. The male and female nuclei move toward each other. Their nuclear envelopes disintegrate. A spindle is formed, and a full diploid set of chromosomes assembles on it. The fertilized egg or zygote is now ready for its first mitosis.<\/p>\n<\/td>\n<\/tr>\n\n\n
\n \n<\/tr>\n \n \n A2 Option Module 8\u00a0 BEHAVIOUR AND POPULATIONS<\/h4>\n<\/td>\n<\/tr>\n
\n Introduction: This option module extends the study of nervous and hormonal physiology in Module 4 to the behaviour of whole organisms. There is also consideration of reproductive behaviour and human growth and development, with an emphasis on the underlying principles of hormonal control. The study of human populations is developed to include a range of public health issues. Candidates are expected to understand the biological background to these issues and to be able to evaluate possible strategies for improvement. In the assessment of this module a knowledge and understanding of relevant content from Modules 1 to 5 will be assumed.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n\n \n\n
\n Reproduction, human growth and development, human populations<\/strong><\/td>\n<\/tr>\n \n \n \n
\n \n
\n\n
\n Specification table:<\/strong><\/td>\n<\/tr>\n \n Patterns of behaviour<\/td>\n<\/tr>\n \n Innate behaviour<\/td>\n The principal differences between innate and learned behaviour.<\/td>\n<\/tr>\n \n Taxes and kineses<\/td>\n Taxes and kineses as examples of innate behaviour.<\/td>\n<\/tr>\n \n Reflex actions<\/td>\n The nature of simple reflex behaviour, such as in reflex escape responses.<\/p>\n \n Modified reflexes<\/td>\n The modification of reflex behaviour by learning as shown by the development of conscious control of bladder emptying.<\/td>\n<\/tr>\n \n Learned behaviour<\/td>\n Habituation and imprinting.<\/p>\n \n\n
\n Reproductive behaviour<\/td>\n<\/tr>\n \n Courtship<\/td>\n Courtship behaviour as a necessary precursor to successful mating. The roles of species recognition, pair bond formation, sexual selection and synchronisation of breeding behaviour.<\/p>\n \n Territorial behaviour<\/td>\n The advantages of defending a territory, in relation to breeding success.<\/td>\n<\/tr>\n \n The menstrual cycle<\/td>\n The roles of FSH, LH, oestrogen and progesterone in controlling the human menstrual cycle.<\/p>\n \n Contraception<\/td>\n The use of oral contraceptives based on oestrogen and progesterone in controlling fertility.<\/p>\n \n Infertility<\/td>\n The treatment of female infertility with extracted and synthetic hormones and with drugs such as clomiphene which stimulate hormone activity.<\/p>\n \n
\n\n
\n Pregnancy<\/td>\n<\/tr>\n \n Conception<\/td>\n Fertilisation, including capacitation, the role of the acrosome and formation of the fertilisation membrane.<\/td>\n<\/tr>\n \n Hormones and pregnancy<\/td>\n The roles of human chorionic gonadotrophin (HCG) and<\/p>\n \n The placenta<\/td>\n The structure of the placenta in relation to its role in the supply of substances to, and the removal of waste products from, the developing foetus.<\/td>\n<\/tr>\n \n Physiological changes in the<\/p>\n The changes in the following which take place during the course of a normal pregnancy and their physiological significance:<\/p>\n \n
\n\n
\n Human growth and development<\/td>\n<\/tr>\n \n Patterns of human growth<\/td>\n The pattern of growth of the whole body, reproductive organs and the brain from infancy to adulthood.<\/p>\n \n Hormonal control<\/td>\n The roles of thyroxine, growth hormone and sex hormones in the control of human growth from infancy to maturity.<\/p>\n \n Ageing<\/td>\n The contributions to ageing of changes in physiological function, degeneration of tissue, accumulation of genetic error, and malfunction of the immune system.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n \n\n
\n Human populations and health<\/td>\n<\/tr>\n \n Population size and structure<\/td>\n Population growth rates, pyramids, survival rates and life expectancy.<\/p>\n \n
\n Social conditions<\/td>\n The influence of food supply, safe drinking water and effective sewage disposal on mortality.<\/td>\n<\/tr>\n \n Infectious disease<\/td>\n Pathogens, including certain bacteria, viruses and fungi, as the cause of infectious disease.<\/p>\n \n
\n Effects of lifestyle on health<\/td>\n The constitution and importance of a balanced diet. The effects of excess fat and salt intakes, and of deficiency of mineral ions (calcium, iron and iodine) and vitamins (vitamins A, C and D).<\/p>\n \n Screening programmes<\/td>\n The principles involved in the use of x-rays, endoscopy, ultrasound and genetic techniques in diagnosis and screening programmes.<\/p>\n \n\n
\n Behaviour<\/strong><\/p>\n \n
\n Innate Behaviours <\/b><\/p>\n \n
2. Taxis: \u201ca directed movement toward or away from a stimulus; positive and negative taxes
3. Reflex: \u201cmovement of a body part in response to stimulus\u201d.
4. Fixed Action Pattern (FAP): \u201cstereotyped and often complex series of movements., responses to a specific stimulus \u2013 Releaser\u201d<\/p>\n\n Kinesis:<\/strong> An orienting behaviour which is non-directional. Here an animal reduces it\u2019s rate of movement or increases its rate of turning as the intensity of the stimulus increases (e.g. woodlice slow down and turn more in the dark). This action has the effect of keeping the organism in an area it finds favourable and making it move away from areas it finds unfavourable.<\/td>\n<\/tr>\n \n Taxis:<\/strong> An orienting behaviour which is directional. Here an animal turns towards or away from a stimulus such as light. Can be positive or negative. Blowfly larvae (maggots) show negative phototaxis.<\/td>\n<\/tr>\n \n Reflex<\/strong>: A simple reflex<\/strong> is movement of a body part in response to stimulus. It is a rapid, innate automatic response to a stimulus. We looked at the nerve pathway involved in a reflex in module 4 and that helps explain why they are quick and the response does not vary. Watch out for synoptic questions on reflexes.<\/p>\n \n\n
\n Reflex<\/b><\/td>\n Behaviour<\/b><\/td>\n<\/tr>\n \n Rooting reflex (baby)<\/td>\n Also called nipple-seeking behaviour. When the breast touches the baby it will turn its head with its mouth open until it finds the nipple.<\/td>\n<\/tr>\n \n Sucking reflex (baby)<\/td>\n When the baby attaches to the nipple it begins to suck.<\/td>\n<\/tr>\n \n Let-down reflex (mother)<\/td>\n The stimulation of the nipples by the baby sucking causes the reflex release of the hormone oxytocin. This hormone triggers smooth muscle contraction in the mammary glands causing the release of milk<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n \n\n
\n Although reflexes are defined as unconscious actions that are performed in their entirety and are automatic \u2013 they can in some instances be modified. The most obvious example of this is the control of the sphincters which govern urination and defaecation.<\/p>\n \n\n
\n Learned Behaviour<\/strong><\/td>\n<\/tr>\n \n Learned Behaviour can be divided into different categories:<\/p>\n \n
\n Habituation<\/strong> is perhaps the simplest form of learned behaviour. This is where an animal that normally responds to a certain stimulus learns to stop responding to the same stimulus when it is repeatedly stimulated without reason. For example some spiders lie in wait for prey to one side of their web and when something gets trapped. On the web the spider detects the vibrations of the web a rushed out to kill its prey. This response can be made to occur by simply tapping the web with a pen. However after a few stimuli the spider ceases to respond. We say it has become habituated.<\/p>\n \n Conditioning<\/strong> involves the formation of new connections between stimuli and responses, the table below shows a summary of this<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n \n\n
\n Type of conditioning<\/b><\/td>\n Summary<\/b><\/td>\n<\/tr>\n \n Classical<\/td>\n A stimulus leads to a response. Here a new stimulus is given at the same time as the first after time the response occurs even if only the second stimulus is given.<\/td>\n<\/tr>\n \n Operant<\/td>\n Trial and reward learning.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n \n\n
\n Classical conditioning was first shown by the work of Pavlov with dogs. He collected saliva from dogs and noted that when presented with the sight and smell of their food they began to salivate in preparation of eating. Pavlov began to ring a bell each time the dog was shown their food. After a while Pavlov found that the dogs salivated when the bell was rung regardless of whether food was present. The dog had become conditioned it associated a bell with the arrival of food.<\/td>\n<\/tr>\n \n \n<\/tr>\n \n Habituation<\/strong><\/p>\n \n Imprinting<\/strong><\/p>\n \n The Conditioned Response<\/strong><\/p>\n \n\n
\n We use the term \u201coperant conditioning\u201d to describe one type of associative learning. Operant conditioning is also termed trial and reward learning. The\u00a0 classic experiments into operant conditioning were carried out by Skinner, where he trained rats and pigeons to press a lever in order to obtain a food reward (\u201cskinners box). In such experiments, the subject is able to generate certain motor-output responses<\/em> (e.g. running around, cleaning, resting, pressing the lever). The experimentor chooses a certain action (e.g. pressing the lever) to act as the response and to pair with an unconditioned stimulus<\/em> (e.g. a food reward). After a training period, the subject will show the conditioned response<\/em> (e.g. pressing the lever) if the response-unconditioned stimulus association has been memorized.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n \n\n
\n Pheremones<\/strong>Pheromones are chemicals released by an organism into its environment enabling it to communicate with other members of its own species<\/strong>.<\/td>\n<\/tr>\n \n \u00a0<\/p>\n \n
\n\n
\n Courtship<\/strong><\/p>\n \n
\n
\n In establishing breeding partners and defending territories members of the same species rarely fight. Instead they take part in behaviour that is stylised and aimed at avoiding the need to fight<\/p>\n \n
\n
\n
\n Types of mating relationships<\/strong><\/p>\n \n
\n\n
\n The Hormonal Control of the Female Menstrual Cycle<\/strong><\/p>\n \n Pituitary Hormones<\/strong> \u2013 released from the pituitary gland in the brain<\/p>\n \n
\n
\n The sequence<\/strong><\/p>\n \n
\n\n
\n Summary of effects<\/strong><\/td>\n<\/tr>\n \n Hormone<\/strong><\/td>\n Effects<\/strong><\/td>\n<\/tr>\n \n FSH<\/td>\n \n \n
\n LH<\/td>\n \n \n
\n Oestrogen<\/td>\n \n \n
\n Progesterone<\/td>\n \n \n
\n\n
\n Fertilisation<\/strong> Summary:<\/strong><\/p>\n \n Fertilisation<\/strong> Detail:<\/strong><\/td>\n<\/tr>\n \n Copulation and Fertilization<\/strong><\/p>\n \n \n<\/tr>\n \n \n<\/tr>\n \n \n<\/tr>\n<\/tbody>\n<\/table>\n \n\n