Unit 7 Hormones And The Endocrine System

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Unit 7

Hormones and the Endocrine System

That role of the endocrine system and its six endocrine glands.

That hormones target specific tissues away from their site of production.

That a response to a hormone can last from seconds to many years.

The role of adrenalin during the ‘fight or flight’ response in humans.

The role of ADH in controlling blood and tissue fluid levels.

The role of insulin and glucagon in controlling blood sugar levels.

That there are two types of diabetes in humans.

The role of the female reproductive system.

That the menstrual cycle is controlled by several hormones.

Contraceptives including the pill.

That barrier contraceptives help prevent sexually transmitted diseases like AID s and hepatitis.

Endocrine, Gland, Hormone, Target, Tissue, Effect, Response, Insulin, Glucagon, Adrenaline, Blood, Sugar, Diabetes, Reproductive, System, Oestrogen, Progesterone, Pill Follicular stimulating hormone, Leutinising hormone, Menstrual, Cycle, Contraceptives, Condom, Dutch cap, Femidom, AIDs, HIV, Gonorrhoea & Chlamydia. Unit 7 Hormones and the Endocrine System web: www.science-interactive.co.uk email: sales@science-interactive.co.uk Science Interactive LTD PO BOX 50764 LONDON NW6 9AT Click mouse to begin Science Interactive LTD Copyright 2005 Understand: Keywords:

Overview of the endocrine system The endocrine system, like the nervous system plays a major role in coordinating your body. There are six major endocrine g________, able to manufacture and release hormones into the bloodstream of the human body. Hormones instruct tissues in the body what to do. These response may last a few seconds or many years. Hormones can affect growth, sexual development, aggression, blood sugar levels and even your metabolism. Correct levels of all your hormones are essential for normal healthy growth and development. What condition is caused by a lack of insulin ? The endocrine system in humans: Science Interactive LTD Copyright 2005 Word bank: gland pancreas adrenalin testosterone T_____________ Testis Oestrogen Ovaries A_____________ Adrenal glands Insulin/glucagon P_________ Thyroxine Thyroid gland ACTH and ADH Pituitary Hypothalamus Hormone released Endocrine gland Endocrine glands like the thyroid and pituitary release hormones into the blood, which then travel to a target tissue and produce a response. These responses can last seconds or even years. Notes Diagram Male and female endocrine system

Hormones functioning at the tissue level Hormones like testosterone or i__________ that target specific tissues, unlike the nervous system, cause a slow response and usually result in a change in tissue function and or growth rates. Hormones can be released into the blood over many hours, days or even years. Testosterone, released during male p__________, remains elevated from puberty for the rest of a man’s life. Testosterone is what triggers the development and continuation of male secondary sexual characteristics. Tissue response to hormones: Science Interactive LTD Copyright 2005 Word bank: insulin puberty Testosterone is produced by the testis. Production surges during puberty. Testosterone enters the bloodstream and is transported to target tissues like the muscle, testis and skin. This hormone causes different genes in different cells to produce new proteins for growth and development. These are just a few of the changes that occur during puberty in boys, all caused by one single hormone over several years: testosterone. Notes Diagram Effects of testosterone around the body’s tissues Testosterone

Hormones in action Hormones like insulin, thyroxine and ADH help keep conditions in the body, like sugar levels, metabolism rates and water levels constant. The control of bodily water levels relies on feedback . The brain (pituitary) monitors the levels of water in the blood. When these levels begin to fall ADH is released, which begins to act on the target t________ and restore the body’s water levels. At this point the brain ceases to make and release any more ADH . Keeping conditions stable inside the body is called h_____________ and hormones help with this. Anti diuretic hormone (ADH) Increasing ADH Reduced ADH Normal Low blood water High blood water Science Interactive LTD Copyright 2005 Word bank: tissue homeostasis The amount of water in your blood is controlled by the actions of a hormone called anti diuretic hormone (ADH) on your kidney. On a hot summers day for example, you lose water through your skin as sweat. If you fail to replace lost fluids by drinking, your blood volume begins to drop. This triggers the pituitary to produce ADH. ADH then travels and targets the kidney. Water is then reabsorbed from the kidneys back to the renal vein, therefore reducing water loss. Your urine is low in volume and very concentrated. Notes Diagram Effect of ADH around the body’s tissues Water levels

ADH controlling body water one The amount of water in your body and circulatory system and the quantity you excrete in u________ is controlled by the actions of a hormone called anti diuretic hormone ( ADH ). ADH is made by your pituitary gland found in your b______, in response to low blood volume or pressure. The ADH hormone travels in the blood from the brain, to the kidney. It then acts on the nephron’s loop of henle to increase the amount of water reabsorbed back into the renal vein. What is the difference between the urine you excrete on a hot summer’s day and a cold winter’s day ? Water gains and losses: Science Interactive LTD Copyright 2005 Word bank: urine brain Water losses include: 1: Water in exhaled air (12%) 2: Faeces (3%) 3: Sweat (25%) 4: Urine (60%) Water gains include: 1: Cellular respiration (10%) 2: Drinking fluids (70%) 3: Food (20%) Notes Diagram Water gains Water losses

ADH controlling body water two The amount of water in your body and blood vessels and the quantity you excrete as u_________ is controlled by the actions of a hormone called anti diuretic hormone ( ADH ) on your kidney. This feedback mechanism allows the body to finely control fluid levels in the blood and other tissues like the brain. Without feedback, our body would not be able to keep us correctly hydrated. Correct hydration is important to allow the right blood volume and pressure. What happens to blood pressure if blood volume falls ? Overview of ADH in the body: Science Interactive LTD Copyright 2005 Word bank: urine Collecting duct takes small volumes of concentrated urine to the bladder. The loop of henle and the distal tubule starts to reabsorb water. ADH hormone is carried to the kidney via the renal artery. The brain starts to produce ADH from the pituitary gland. Too little water The loop of henle and distal tubule stops absorbing water. The nephron Collecting duct takes large volumes of dilute urine to the bladder. No ADH hormone carried to the kidney via renal a_______. The brain stops producing ADH from the pituitary. Too much water Diagram Brain Blood supply Urine volume

Adrenalin and the stress response one Increasing adrenalin Reduced adrenalin Normal High arousal & stress Low arousal & stress Adrenalin, known as the ‘fight or flight’ hormone readies the body and its organ systems in response to s_______ or a potential threatening situation. The overall effect of adrenalin is to help your body cope with an emergency. This can be a low level response, for example when you are taking examinations or a high level response to an imminent threat, for example if you are attacked. Overview of the activation of the ‘fight or flight’ response: Science Interactive LTD Copyright 2005 Word bank: stress A stressor, for example a threat of physical attack or exams is detected by your brain. The brain responds to this elevated stress and starts to activate the sympathetic nervous system. The adrenal glands, which sit above the kidneys receive electrical impulses from the brain. Adrenalin hormone is released into the blood, circulating around the entire body. Notes Diagram Effect of adrenalin around the body’s tissues Levels of arousal

Adrenalin when released into the blood causes several responses to ready the body for ‘ fight or flight .’ You may have noticed, in yourself an increase in your h_______ and breathing rate, increased alertness (hearing and sight), increased blood pressure and reduced appetite when threatened by somebody. During exams, low level stress can give you that ‘sensation of butterflies’ in the stomach as well as a dry m_______, sleepless nights and general worry. This is low to moderate level stress. Overview of the response of organs to adrenalin: Adrenalin and the stress response two Science Interactive LTD Copyright 2005 Word bank: heart mouth Lungs Brain: Your brain and your senses, like eyesight and hearing become more alert. Heart and cardiovascular system: Heart rate and blood pressure increase in readiness for possible attack or escape. Lungs: Breathing rate increases to supply more oxygen to the muscles in the body. Skeletal muscle system: The skeletal muscle system performs better due to an increased oxygen supply. Response Diagram Brain Heart Muscle system

Insulin and controlling blood glucose one Every respiring cell requires glucose and oxygen. Glucose is transported from your dietary intake and stored glycogen by the cardiovascular system. All food types including proteins, c______________ and fats can be converted into g_________ by enzymes present in the body. Carbohydrates and dietary sugar provide the majority of your bodily glucose. Western diets often have too much refined sugar, which can lead to diabetes, excessive tooth decay and of course obesity. Sources of glucose in the human diet: Science Interactive LTD Copyright 2005 Word bank: carbohydrates glucose In your daily intake of food, there are many direct and indirect sources of glucose. Fizzy drinks, chocolates and sweets contain a high percentage of glucose which is then absorbed into the blood and stored as glycogen in the liver, fat and muscle tissue. Indirect sources of glucose like carbohydrates have to be broken down to glucose by digestive enzymes before absorption into the blood and its use by respiring cells. Foods containing sources of direct and indirect glucose Diagram

Insulin and controlling blood glucose two Our dietary intake of foods like proteins, carbohydrates and lipids should provide us with the correct amount of c_________ energy to maintain our daily activities, growth (if we are children) and repair. An adult male requires about 10,500 kJ per day, equivalent to about 100 joules per second. This is the same energy that a 100 watt light bulb uses. Taking too much energy, by perhaps consuming too much raw s_______ can lead to weight gain, high blood pressure and eventually obesity. Sources of glucose in the human diet: Science Interactive LTD Copyright 2005 Word bank: chemical sugar C 6 H 12 O 6 6O 2 6CO 2 6H 2 O Mitochondria Energy Respiration Growth & reproduction Assimilation Dietary energy Respiration 10,500 kJ/day (adult male) Glucose is used by all cells during respiration. This is provided by the food we consume in our diets. The body needs to control the amount of glucose in our blood. Two hormones do this; insulin and glucagon both produced in the pancreas. Notes Diagram Dietary intake, assimilation and respiration

Glucagon Normal Low blood glucose <900 mg/l

Your blood sugar and insulin levels rise and fall during the day. This depends on:

Amount of s_________ intake through your diet.

Amount of energy used by the b______.

Control of blood glucose and glycogen by insulin and glucagon.

Overview of the role of insulin and glucagon in controlling blood glucose:

Insulin High blood glucose >900 mg/l <900 mg/l >900 mg/l 900 mg/l Insulin and controlling blood glucose three Science Interactive LTD Copyright 2005 Word bank: sugar body Hormone Receptor Cell membrane Cytoplasm Activation of the cellular responses Insulin: (>900 mg/l) Increased conversion of blood glucose to glycogen and its storage in liver and muscle tissue. Blood glucose decreases. Glucagon: (<900 mg/l) Increased conversion of glycogen to glucose from the muscle and liver tissue. Blood glucose rises. Blood glucose levels is tightly controlled by two hormones released by the pancreas; insulin and glucagon . Too much or too little glucose in the blood can lead to death. Diabetics cannot produce insulin. This leads to very high glucose levels, following intake of food containing glucose or carbohydrates. Notes Diagram Effect of insulin and glucagon around the body’s tissues Blood glucose levels

Both glucagon and insulin, made and released by the pancreas control blood glucose levels. Insulin is able to lower blood glucose, whereas glucagon is able to increase blood glucose. These hormones ensure that, despite different intakes of glucose from dietary sources, blood glucose levels are always the same at 900 mg per litre of blood. Overview of the role of insulin and glucagon in controlling blood glucose: Insulin and controlling blood glucose four Science Interactive LTD Copyright 2005

Your blood sugar and insulin levels rise and fall during the day. This depends on:

Amount of s_________ intake through your diet.

Amount of energy used by the b______.

Control of blood glucose and glycogen by insulin and glucagon.

Blood glucose levels:

Insulin and controlling blood glucose three Science Interactive LTD Copyright 2005 Word bank: sugar body +++++++++++++++++++++ + + + + + + + + + + +++++++++++++ + + + + + + + + + + + + + ++++++++ + + + + + + + + ++++++++++++++++ +++++++++++++++++++ + + + + + + + + + + +++++++++++++ + + + + + + + + + + + + + ++++++++ + + + + + + + + ++++++++++++++++++ Notes: Time Graph Shown by the graph are blood levels of glucose ( + ) and insulin ( + ) after a carbohydrate meal at 8 a.m., 12 p.m. and 8 p.m. Note that the peak of blood insulin is reached shortly after peak levels of blood glucose. Insulin levels remain elevated for some time after the glucose has returned to normal levels.

Diabetes A diabetic cannot control their own blood sugar. Their blood sugar levels can become dangerously high. If untreated this can lead to weight loss and even death. There are two types of diabetes: Type 1 The pancreas fails to produce insulin, therefore glucose is not able to be stored as glycogen in liver or muscle tissue. Type 11 The pancreas produces insulin, but not enough to help adequate amounts of glucose to be stored as glycogen in liver or muscle tissues. Types of diabetes: Key: Glucose Insulin Liver cell Science Interactive LTD Copyright 2005 Not enough insulin is made by the pancreas, allowing only a limited amount of glucose storage in the liver and muscle. Type II diabetes Diabetics control their sugar by: Injecting insulin. Insulin tablets. Low sugar diet. No insulin is produced by the pancreas, therefore glucose is unable to be enter the cell and be stored. The hormone, insulin produced by the pancreas is the key to helping glucose enter cells of the muscle and liver. Notes Insulin Diagram Normal function Type I diabetes

Risk factors for diabetes It is estimated that if current trends continue one in ten individuals in Britain will suffer diabetes at some time in their lives. Although diabetes can be treated by injecting i________ during meal times to help control blood g________ levels, there are still health consequences for the diabetic. Heart failure, sight loss and kidney damage can reduce life expectancy by up to 10 years. There are risk factors associated with developing diabetes. They include, eating excessive amounts of sugar, your family history, your body weight and alcohol intake. Risk factors for the onset of diabetes: Science Interactive LTD Copyright 2005 Word bank: insulin glucose Obesity What you do in your life affects your chances of developing diabetes. If you have a family member who has developed diabetes, are Asian in origin, are overweight, drink excessively or consume too much raw sugar, these factors can all significantly increases your risk of developing diabetes and of course other health consequences like heart and kidney failure. Living with diabetes is a 24/7 task with no respite. Notes Alcohol Diagram Sugar intake Family history

Living with diabetes One in twenty British people now live with diabetes. If current trends continue, over the next fifty years, an estimated one in ten or six million people will suffer from type one or two diabetes. Living with diabetes means you have to tightly control the amount of s______ in your diet, regularly inject insulin and test you b_______ glucose levels before and after meals. Children who suffer diabetes find it especially difficult because of their like for sweets and drinks that are full of sugar. Living with diabetes: Science Interactive LTD Copyright 2005 Word bank: sugar blood Blood tests Currently over 3 million British people young and old live with diabetes every day. Regular injections of insulin, blood tests and health screens are part of normal life. Diabetics need to control the amount of raw sugar that they take in their diets. Too much can lead to an increased risk of heart and kidney failure. In the near future, gene therapy will cure diabetics and reduce the need for injected insulin. Notes Injecting insulin Diagram Diabetic Hospital check ups

Female reproductive system The role of the female reproductive system is to produce and release e___ cells from the beginning of puberty through to the female menopause. Over about 35 years in females, a single egg is released every month ready for male s_______ and fertilisation. The zygote then starts to divide and implants itself in the uterus wall. There it develops over nine months with the help of the placenta until birth. How does the contraceptive pill prevent pregnancy ? Female reproductive system: Science Interactive LTD Copyright 2005 Word bank: egg sperm ovaries urethra Receives sperm from the male penis during intercourse. _________________________ ? Protects developing foetus, supplies oxygen and nutrients via the placental blood supply. _________________________ ? _________________________ ? Stores and release the egg. Function (complete) Vagina Cervix U______ Ureter Egg tubes O______ Organ/tissue

Ovulation and the female menstrual cycle one Hormones from the pituitary gland and the ovaries control the female menstrual cycle: FSH from the pituitary gland starts the cycle and instructs the ovary to produce an egg. Oestrogen released by the o_________ begins to thicken the uterus lining. Leuteinising hormone , from the pituitary gland peaks at day 14 causing the ovaries to release the egg. It also causes progesterone to be released which makes the uterus lining even thicker. If pregnancy occurs, progesterone and oestrogen continue to be released to ensure that the uterus lining supports the developing e________. Also the woman’s menstrual cycle is stopped preventing menstruation and further release of eggs. The female menstrual cycle: Science Interactive LTD Copyright 2005 Word bank: ovaries embryo The monthly menstrual cycle which lasts about 28 days readies the female womb for implantation of a fertilised egg. The whole event is controlled by four hormones: FSH, LH, oestrogen and progesterone . Overview of the female menstrual cycle. The menstrual cycle

Ovulation and the female menstrual cycle two During the female menstrual cycle, which normally begins between 9 and 13 years, the lining of the u_________ begins to thicken. The egg cell also matures inside the ovaries. The uterus wall after 14 days is ready to receive a fertilised egg which is released during ovulation on day 14. If fertilisation does not occur, the unfertilised egg passes out of the v__________. Some days later, the uterus wall breaks down and small amounts of blood and tissue pass out of the vagina during the period. More about the menstrual cycle: Science Interactive LTD Copyright 2005 Word bank: uterus vagina FSH from the pituitary gland starts the cycle and instructs the ovary to produce an egg. LH hormone, another hormone from the pituitary gland peaks at day 14 causing the ovaries to release the egg. If a fertilised egg has not been implanted, oestrogen and progesterone stop being produced and the uterus wall starts to break down. Period begins with loss of tissue and blood from the breakdown of the womb. Overview of the female menstrual cycle. The female womb

Barrier contraceptives and the pill Barrier contraceptives including c___________ are used to control pregnancy and reduce the risk of contracting sexually transmitted diseases (STDs) like HIV, Candida, Gonorrhoea and Syphilis. Other methods, although able to reduce the incidence of unwanted pregnancies, do not protect you or you partner against STDs. These include the cap and the hormone pill. Why should you only use the pill in a long term relationship ? Contraceptives: Science Interactive LTD Copyright 2005 Word bank: condoms Femidom Condoms: The condom is worn by the male to prevent sperm from entering the vagina and prevent the transmission of STDs like HIV and Syphilis. Barrier cap: The cap or diaphragm is a rubber dome which sits over the cervix inside the female vagina. It does not prevent transmission of STDs. Femidoms: The femidom, a recent addition to barrier contraceptive methods sits inside the vagina and prevents sperm reaching the egg. Contraceptive pill: The pill is normally used for long term contraception within a stable relationships. It does not prevent the transmission of STDs. Notes Diagram Contraceptive Condom Cap Pill

Sexually transmitted diseases An important role for barrier contraceptives like condoms is to protect both the male and the female against contracting s___________ transmitted diseases including HIV, Gonorrhoea, Syphilis and Chlamydia. Some sexually transmitted diseases like HIV are fatal with no known cure. Some STDs like Chlamydia can leave f_________ infertile if left untreated. Why is it important for everybody to take their own responsibility for contraception and avoid STDs by using barrier methods. Sexually transmitted diseases: Science Interactive LTD Copyright 2005 Word bank: sexually females Gonorrhoea Condoms: Condoms worn by the male offer the best protection against all sexually transmitted diseases including AIDs. This virus is estimated to kill over 5 million people a year. Aids: AIDs a virus that first surfaced in San Francisco in 1984 is estimated to have killed over 10,000,000 humans. Your risk of contracting AIDs is high if you have unprotected sex. Gonorrhoea: Gonorrhoea can now be treated by modern drugs if caught early on. It produces a yellow discharge in men and women. This disease can be lethal if left untreated. Chlamydia: Chlamydia in women left untreated can lead to infertility. 1 in 10 women and men carry this bacteria. Most don’t know they are carriers. Notes Diagram Condoms AIDS Chlamydia

Using hormones to control pregnancy one Hormones can be used to prevent or reduce the chances of falling pregnant in females. Hormones as a contraceptive: The female contraceptive pill contains hormones which prevents the ovaries from releasing the e_____ during the monthly menstrual cycle. It is extremely reliable, but does not protect the user from sexually transmitted diseases. The pill can also cause side effects in some women including weight gain, headaches and high blood pressure. Why is the pill not suitable for all women particularly over the long term ? Hormones controlling pregnancy: Pill is about 99.5% effective as a female contraceptive . STOP Science Interactive LTD Copyright 2005 Word bank: egg Pregnancy testing Contraceptive pill: The pill is widely used by many women who do not want to conceive within a relationship. The oral contraceptive pill is not effective at preventing STDs and should only be used in a stable relationship, where the sexual history of the male partner is known. Can cause weight gain, blood pressure increases and an increased risk of developing breast cancer. Notes Diagram Contraceptive pill Not raising a family

Using hormones to control pregnancy two Hormones can also be used to increase the chances of falling pregnant in females. Hormones helping couples conceive. Fertility treatment using h___________ can help females who fail to produce an egg during the menstrual cycle. Women take follicular stimulating hormone (FSH), which helps stimulate the ovaries into producing one or more e_______. Consequently fertility treatment can give rise to multiple embryos. This can result in twins, triplets and even more ! Why has the number of twins (non identical) risen since fertility treatment started ? Hormones controlling pregnancy: FSH treatment is about 25% effective in women. There is an ever increasing number of twin births because of FSH treatment. Science Interactive LTD Copyright 2005 Word bank: hormones eggs Pregnancy testing Fertility treatment: Many couples who want to conceive and raise a family find it impossible to do so. One of the first interventions is to administer FSH which stimulates the ovary to release eggs during the female menstrual cycle. This is relatively successful for about 25% of women. Because of FSH treatment the number of pregnancies with twins is rising. Notes Diagram Fertility treatment pills Raising a family

General fertility treatment Many couples who remain unsuccessful when trying to conceive are first treated with the hormone FSH. Following this treatment, other fertility treatments are available. These include intrauterine (sperm) insemination (IUI), Egg donation or retrieval and In vitro fertilisation. The first child to be conceived by this last method has just celebrated her 25 th birthday. Most couples are offered six cycles of treatment for infertility by the NHS. Fertility treatment: Science Interactive LTD Copyright 2005 Egg retrieval and donation takes healthy eggs and freezes them. The egg is then fertilised outside the womb and implanted within 12 hr into the female womb. Egg donation In vitro fertilisation is offered often when the females fallopian tubes become blocked. The sperm is injected into the egg then implanted directly into the womb. IUI: Intrauterine insemination takes washed sperm from the male and injects them directly into the womb using a syringe like device. Often males fail to produce enough sperm during their ejaculation. Also the sperm produced can be abnormal in shape or have very low motility or movement. Notes Diagram Sperm health IUI In vitro fertilisation

Meiosis leads to the formation of only two types of cells. Meiosis in males forms the s______ and in females the o______ or egg cells. Meiosis halves the number of chromosomes, so that when the sperm and egg fuse, the fertilised zygote will have the correct number of chromosomes ( 23 chromosomal pairs) Meiosis also produces random gene mixing leading to variation of human traits in new individuals. Gamete production in the male and female: sperm egg Reproduction in humans Science Interactive LTD Copyright 2005 Word bank: sperm ovaries All of these 31,000 genes code for all the traits and characteristics that make human life unique. Cells now divide by mitosis. After fertilisation, all cells of the developing embryo now contain 23 pairs of chromosomes with over 31,000 genes. Sperm and eggs cells are haploid with only 23 single chromosomes only half the normal number Gametes cells (sperm and egg) are produced by the testis and ovaries in the male and female. Pregnancy Embryo Fertilisation Gametes

Your chromosomes also determine what sex you are at b_______. In humans there are 23 pairs of chromosomes found in every cell. 22 pairs are identical, but pair 23 do not match. Pair 23 are called the sex chromosomes. All eggs from the female contain the X chromosome, sperm from the male contain either the X or Y chromosome. At fertilisation, the egg may join with either an X or Y sperm producing equal numbers of males ( XY ) or females ( XX ). What are the gametes cells called in plants ? Inheritance of the sex chromosomes: Determining your child’s sex Science Interactive LTD Copyright 2005 Word bank: birth During fertilisation, the number of chromosomes are restored to their normal diploid number (23 pairs) The embryo now grows by normal cell division called mitosis. The gamete cells (sperm and egg) carry only 23 single chromosomes. They are haploid cells. Your sex is determined at the moment of fertilisation by the male sperm. An X carrying sperm produces a girl, and a Y carrying sperm produces a boy. There is a 50: 50 chance of either sex. Sex inheritance Gamete cells Female Male

Designer babies Understanding what genes in Humans, code for which human characteristics will allow scientists to screen developing foetuses for inherited d__________ like sickle cell anaemia and other diseases like cancer and mental illness. Eventually scientists could even give parents information about their offspring like e____ and hair colour, behaviour and even intelligence. Parents could then begin to screen and select their children on the basis of the child’s genes or DNA . This could lead to so called designer babies. Do you think that this is an ethical use of such information ? Designer babies: Science Interactive LTD Copyright 2005 Word bank: diseases eye Hair colour Eye colour: The eye colour of the new baby can be determined by genetic testing. Hair colour: The hair colour can also be determined by knowing the genes that are carried by the foetus. Intelligence: Gene indicators for intelligence and even behaviour maybe discovered in the near future. Parents may decide to terminate a pregnancy on this advice. The foetus’s DNA profile is determined during pregnancy by analysis of a small sample of cells. Notes Diagram Gene testing Eye colour Behaviour/intelligence

Cloning humans The future one Cloning humans has been made possible by technology developed by British scientists who first cloned sheep: Molly and Dolly. In January 2005, an American scientist made claims on World News that he and his team had cloned the first human, although the identity of the donor and the family involved remains secret. Like scientists who cloned Molly and D______, DNA from the skin cell of a male was placed inside a female donor egg that was emptied of its DNA . If the pregnancy succeeds the birth of first human clone will raise the question: What have we done in the name of science ? Cloning humans: Science Interactive LTD Copyright 2005 Word bank: dolly A new world is born with the birth of the first human clone, but when will it happen and who is it ? Clones The developing embryo is then implanted into the womb of a surrogate mother for nine months until birth. Implantation The DNA from a human donor is placed inside an empty egg cell. An electric current is used to start cell division. Replacing genes DNA from the human to be cloned is taken from a single skin epithelial cell. Notes Diagram Skin DNA

Headlines everyday claim that scientists have cloned the first Human. Genetic engineering makes it possible to produce human c________ using similar technology first used to clone the sheep Molly and Dolly. How many days, months or years are we from the fist Human clone, only time will tell ! Cloning Humans: Donor cell Donor egg Donor cell Donor egg Fusing cells are shocked Fused cell contains 23 pairs of genes Embryo is placed inside a host womb Cloned Human Host female Cloning humans The future two Science Interactive LTD Copyright 2005 Word bank: clones Stage five Stage six Stage four Stage three Stage two Stage one Stage one: A donor cell is taken from the skin of the male and an egg cell is taken from a female. Stage two: The egg is emptied of its genes and the two cells are allowed to fuse. Stage three. A small electric charge is applied across the two fusing cells. Stage four: The zygote now contains 23 pairs of chromosomes identical to the donors cells. Stage five. Like any other normal zygote, the cell starts dividing. It is then implanted into a host womb, where it develops during a normal pregnancy. Stage six: Nine months later a Human clone of the donor is born.

1: Define the following terms: Endocrine, Gland, Hormone, Target, Tissue, Effect, Response, Contraceptives & STDs. 2: Look at the diagram of the three endocrine glands. Complete the table. 3: Explain the differences between: a) The nervous and endocrine system. b) The time taken for a nerve impulse and a hormone to act. c) Sexual and Asexual reproduction. d) Internal and external fertilisation. e) The hormone produced by the ovaries and the hormone produced by the testis. f) Secondary sexual characteristics in males and females. g) Barrier and hormonal contraceptives. Extension questions and homework Thyroid Pancreas Testis Science Interactive LTD Copyright 2005 Targeted tissue Testis Pancreas Thyroid Effects of the hormone on targeted tissue Hormone produced Microbe

4: Look at the information in the table below. It shows a patient’s blood glucose levels over time following a single insulin injection : a) What is the lowest value of blood glucose. b) At what time was this recorded. c) What happened to cause the blood glucose level to fall. d) Why does the blood glucose level start to rise again. 5: Look at the diagram of the male reproductive system: a) Name the parts labelled A to D. b) Which part is responsible for the following: (i) Making sperm. (ii) Passing semen into the vagina of the female. (iii) Carrying sperm from the testis to the penis. 6: Complete the following: After a meal containing c____________ our blood sugar begins to _______. The pancreas makes a hormone called ___________. This converts glucose to ____________ which is stored in our liver and ____________ cells. During a race, our blood sugar begins to _________ which causes the pancreas to make another hormone called _____________. This converts stored ____________ back to glucose. Internet: Go to google.co.uk and find about how STDs like HIV and Syphilis can be prevented by using barrier contraceptive methods. Also find out about infertility treatment for infertile couples using hormones, IUI and In vitro fertilisation. A B C D Science Interactive LTD Copyright 2005 100 10 70 30 78 80 67 70 45 50 50 40 100 55 95 100 Blood glucose mg/100 cm 3 90 60 20 0 Time (minutes)