B7 Biology ‘triple science’ Route map Over the next 12 lessons you will study : Friday 21 October 2011 B7.1 Harvesting the sun’s energy B7.2 Trapping light energy B7.3 Plants using glucose B7.4 The rate of photosynthesis End of module test B7.5 Respiration and photosynthesis B7.6 Feeding relationships B7.14 Genetic testing B7.15 Blood B7.16 Blood groups and inheritance B7.17 The heart B7.18 Circulation and valves B7.19 Energy B7.8 Symbiosis in food chains B7.9 Parasites in food webs B7.10 Parasites and disease B7.11 Using biotechnology B7.20 Exercise in humans B7.21 Anaerobic respiration and ATP B7.22 The skeleton B7.23 Joints and movement B7.12 Genetic modification B7.13 GM crops and their use B7.24 Sport injuries B7.25 Exercise and training B7.7 Life in soil
B7.15 Genetic testing Decide whether the following statements are true or false: <ul><li>Lesson objectives: </li></ul><ul><li>Understand that genetic test are used to identify faulty genes in both adults and humans </li></ul><ul><li>Understand how DNA technology is used to allow genetic testing to occur </li></ul>Friday 21 October 2011 First activity: Cystic fibrosis runs in your family. Explain what advise you would give an expectant mother in your family if she was about to consider having her developing foetus genetically tested for cystic fibrosis ? Literacy: Genetic testing, DNA, genes, chromosomes, probes, genetic fingerprinting, autoradiography and DNA sample Numeracy: The first genetic tests were launched in the 1980s and were used to identify inherited disorders like cystic fibrosis, down’s syndrome, sickle cell anaemia and haemophilia. PLTS Independent enquirers Creative thinkers Reflective learners Team workers Effective participators Self managers We will focus on t
Decide whether the following statements are true or false: Introduction: Genetic testing launched in the 80s was developed to identify a number of inherited genetic disorders including cystic fibrosis and sickle cell anaemia. Genetic testing uses artificially made pieces of DNA called gene probes. These probes will identify a faulty gene form a DNA sample form a developing embryo or foetus. The probes is usually attached to a fluorescent maker so a positive results will where a faulty gene is identified, it will glow under UV light. Extension questions: 1: Give three genetically inherited disorder that are now routinely test for using gene probes ? 2: A person with cystic fibrosis is life limited...what does these mean ? 3: Is it right to terminate a pregnancy if an inherited diseases is identified in the foetus ? 4: Do you think parents should be allowed to use similar technology to determines a baby’s a) eye colour b) intelligence c) risk of contracting a cancer like breast or prostrate cancer and d) risk of suffering a stoke or heat attack ? Know this: a: Know what inherited diseases can be identified using genetic testing. b: Know how genetic testing work and how gene probes can identify faulty genes. Friday 21 October 2011 B7.15 Genetic testing
Key concepts B7.15 a Look at the photograph and information and answer all the questions: T Why would parents ant to genetically test their unborn foetus ? Describe how a gene probe can be used to identify a faulty gene that would cause an inherited disorder like cystic fibrosis ? Parents with a family history of inherited disease can now request a genetic test on their unborn baby. A small amount of amniotic fluid is remove and tested with gene probes that can identify diseases including sickle cell anaemia, haemophilia, Down’s syndrome and cystic fibrosis. During the procedure there is a small risk of termination.
Key concepts Look at the photograph and information and answer all the questions: B7.15 b Genetic tests for mutations in single genes that are causally related to rare diseases and are inherited in a simple mendelian fashion can have profound implications for the individual and family members. Genetic tests for inherited diseases including cystic fibrosis, haemophilia, sickle cell anaemia and down’s syndrome. If an inherited disorder is identified, parents are able to decide and access counselling should they wish to give birth to a baby with a life limiting genetic disorder. <ul><li>A husband and wife discovered that they are both carriers of the cystic fibrosis gene </li></ul><ul><li>what advice would you give them ? </li></ul><ul><li>how could genetic testing help them make an informed decision if the wife fell pregnant ? </li></ul>Sickle cell ? Haemophiliac ? Cystic fibrosis ? Down’s syndrome ?
B7.15 Plenary Lesson summary: Decide whether the following statements are true or false : False True 3: Cystic fibrosis cannot be identified by genetic testing ? False True 2: Genetic tests were first developed in the 1960s ? False True 1: A gene probe is designed to identify and stick to a faulty gene ? cystic terminated identify foetus Genetic testing can be used to ________ key inherited disease like _____ fibrosis, sickle cell anaemia and haemophilia. By testing an unborn _________, parents can make a informed decision whether to proceed with the pregnancy or _______. Currently several commercial laboratories offer tests for up to 16 genetically inherited disease like cystic fibrosis and sickle cell anaemia. As new gene probes are discovered to identify new genes, it may be one day possible to identify genes responsible for human obesity, heart disease, cancer and even depression How Science Works: Friday 21 October 2011 Research into DNAS finger printing and how this technology is used by police in solving crimes like murder, theft, rape and assault. Preparing for the next lesson:
B7.16 Genetic fingerprinting Decide whether the following statements are true or false: <ul><li>Lesson objectives: </li></ul><ul><li>Understand the stages during the production of a genetic fingerprint of an individual </li></ul><ul><li>Understand that genetic fingerprinting can help police prove your innocence or guilt of a particular crime </li></ul>Friday 21 October 2011 First activity: DNA fingerprinting can rule in or rule out suspects in most crimes where a skin sample, blood or another bodily fluid is found at the scene of a crime. Explain why if your are an identical twin you may avoid a guilty verdict even if DNA evidence links you to the scene of a crime ? Literacy: Genome, chromosomes, DNA, genetic fingerprinting, genetic code, DNA evidence, mini-satellites, restriction enzymes, Numeracy: Currently 4 million people in the UK have their DNA held on a UK wide DNA data base meaning that if they do commit a crime and leave DNA evidence at the scene the police will find, convict and imprison them. PLTS Independent enquirers Creative thinkers Reflective learners Team workers Effective participators Self managers We will focus on t
Decide whether the following statements are true or false: Introduction: Unless we are one of a pair of identical twins we all have a unique set of genes or DNA. DNA fingerprinting can tell us these genes and can also be used to identify a child’s parents or even a guilty suspect during a criminal investigation. DNA fingerprinting extracts a person’s DNA, cuts into shorter pieces using restriction enzymes and then separates out the DNA fragment or mini-satellites of about 30 base pairs using gel electrophoreses. Once the fragments are separated they are made visible using probes that bind to the fragments and cause photographic film to go black. Extension questions: 1: How can DNA fingerprinting both prove your innocence and your guilt ? 2: What type of fluids left at a crime scene can you extract enough DNA from ? 3: How can DA fingerprinting be sued to research a family’s genetic history ? 4: How is DNA fingerprinting used to determine a child’s father where paternity is contested, ? Know this: a: Know how to produce a DNA fingerprint of an individual. b: Know that a DNA fingerprint can identify a criminal or prove a person's innocence. Friday 21 October 2011 B7.16 Genetic fingerprinting
Key concepts B7.16 a Look at the photograph and information and answer all the questions: DNA is extracted form a blood or cell sample and cut into short pieces using restriction enzymes; The DNA fragments from individuals are added to the gel. When an electric current is applied to the solution, the fragments migrate through the gel toward the positively charged pole. They do so at different rates, and so they separate into bands according to length. The smaller the fragment, the farther it will migrate through the gel. The fragments are then bound by specific probes. The gel is the place on top of photographic film. The bands then appear as pictured above left. Give three uses for DNA fingerprinting ? What cuts the large DNA molecules into smaller DNBA fragments or mini-satlellites ? Blood sample taken and DNA extracted using restriction enzymes DNA is separated using gel electrophoresis, probes are prepared, probes bind to the DNA X ray film is placed next to separated DNA. The film is then developed and a pattern emerges of the DNA fragments
Key concepts B7.16 b Look at the photograph and information and answer all the questions: This example shows how DNA fingerprinting can point to a criminal. DNA samples were taken from a crime scene, the female victim and three suspects and the suspect’s sperm in a sexual assault case. The victim’s boyfriend was also tested. The DNA ladders are used to judge the sizes of the DNA fragments. Can you determine which suspect is likely the criminal? In this criminal investigation, the victim’s boyfriends DNA was also analysed ...explain why ? Why are the ladders found in lanes 1 and 8 included in this investigation ? Looking at the DNA evidence who raped the victim, was it suspect 1,2 or 3 ? 1 2 3 4 5 6 7 8 1 Ladder 2 Female Victim 3 Suspect 1 4 Suspect 2 5 Suspect 3 6 Sperm DNA 7 Victim’s boyfriend 8 Ladder Who’s DNA and which suspect is guilty
Key concepts B7.16 c Look at the photograph and information and answer all the questions: Identify which children are genetically related to the mum and dad ? Which son is adopted explaining your answer ? Mum Dad D1 S1 S2 DNA fingerprinting can be used to identify a child’s parents. Each child inherits one set of chromosomes from each parent. This is why children resemble both of their parents. In the example below left, all family members were swabbed for cheek cells. Each member of the family had their DNA analysed. The family consists of a mum and dad, one daughter and two sons. The parents have one daughter and one son together and one son is adopted, sharing no genetic material with either parent
B7.16 Plenary Lesson summary: Decide whether the following statements are true or false : False True 3: The first time police used DNA evidence was to prove a person’s innocence ? False True 2: A father and son will share similar DNA mini satellites ? False True 1: DNA fingerprinting can be used by detectives during a murder investigation ? enzymes size satellites pattern DNA fingerprinting or ________ works by looking at DNA mini ________. A person's DNA is cut by restriction _______ and then run on a gel. They then separated according to the _________ it produce on film. Look at the patterns produced can identify a suspect during a criminal investigation or a father in a paternity case There is currently 250,000 children who have their DNA records on the police DNA database. Some children as young as five have had their DNA taken by the police. In Europe we have the highest percentage of the population (currently about 10 million) on record. How Science Works: Friday 21 October 2011 Research into the role of blood, the roles of each type of blood cell and how blood is transfused from a donor and recipient. Preparing for the next lesson:
B7.17 Blood Decide whether the following statements are true or false: Friday 21 October 2011 PLTS Independent enquirers Creative thinkers Reflective learners Team workers Effective participators Self managers We will focus on t <ul><li>Lesson objectives: </li></ul><ul><li>Understand that a) blood is a moving liquid tissue and b) the role of each component of blood. </li></ul><ul><li>Understand how blood types are matched during blood transfusions. </li></ul>First activity: Discuss the feature of the red blood cell and describe how it is specialised to do its function of carrying oxygen from the lung alveoli to all respiring tissues. Literacy: Blood, circulation, heart, blood cells, veins, arteries, capillaries, red blood cells, plasma, white blood cells, clotting, platelets, blood types and blood transfusions. Numeracy: The numbers when studying the circulatory system are staggering. There are 40,000 km of capillaries carrying 5 litres of blood (4,000,000 blood cells per ml) which is pumped around the body by a heart that pumps on average 72 times a minute until you die.
B7.17 Blood Decide whether the following statements are true or false: Introduction: Living cells require water, salts, nutrients for energy and for building other molecules and oxygen. Waste products including carbon dioxide and urea also need to be transported away from the cell. Diffusion is too slow in large organisms and therefore an internal transport system is required. Whole blood is composed of plasma (liquid), cells and platelets. If whole blood is placed into a tube and centrifuged, the cells and the plasma will separate. Red blood cell contains haemoglobin which binds oxygen form the lung surface as it makes its journey to respiring tissues. Friday 21 October 2011 Extension questions: 1: Name the three types of blood tubes ? 2: The three blood tubes you have just named which one carries blood away from the heat at high pressure, which carries blood towards the heart at low pressure and which is a fine network of thin tubes which allow oxygen and nutrients to diffuse into cells ? 3: What are the tubes called that supply your a) kidneys b) your lungs c) your heart and d) your liver ? 4: Red blood cells…explain why they contain a) haemoglobin and b) have no nucleus ? 5: How many litres of blood does an adult have flowing in their body ? Know this: a: Know the role of blood as a transport system for oxygen, nutrients waste compounds and hormones. b: Know how blood types are matched during a blood transfusion.
Key concepts B7.17 a Look at the photograph and information and answer all the questions: The diagram left illustrates the different types of blood cells. Red blood ells have no nucleus and transport oxygen. Platelets are cell fragments involved in clotting. Leukocytes, also known as white blood cells, are a group of related cell types that involved in immune function. Leukocytes include many different types of cells including neutrophils, eosinophils, basophils, lymphocytes and monocytes. Red blood cells make up about 35 to 45% of the blood volume of an healthy adult. This is called the hematocrit. White blood cells are far less numerous with only about 7000 white blood cells per mm 3 . If you counted the white blood cells of a baby compared to an adult how would your count differ ? T Where would you expect to find dissolve a) glucose b) urea and c) carbon dioxide. Decribe the journey for a molecule of a) urea and b) carbon dioxide ? Blood cells
Key concepts B7.17 b Look at the photograph and information and answer all the questions: All mammals have a ‘closed double circulation, where blood at high pressure is pumped around a network of arteries, veins and capillaries by a powerful four chambered pump called the heart. Blood is pumped to the lungs then back to the heart before being pumped around the entire body. Heart rate and blood pressure change according to the requirements of the body. Explain why active warm blooded animals require blood to be at high pressure ? Describe one difference between an artery and a vein ? What would we expect to find in the plasma and compare the levels of urea in the renal artery and renal vein ? Plasma Platelets Red blood cells The human circulatory system
Key concepts B7.17 c Look at the photograph and information and answer all the questions: Explain why doctors are required sometimes to give a patient a transfusion of blood ? Why is it importance to screen all donated blood for HIV and other blood infections like hepatitis ? How is blood store once collected by the transfusion agency and why do we not pay people to donate blood in this country ? A blood transfusion is a safe, common procedure in which blood is given to you through an intravenous (IV) line in one of your blood vessels. Blood transfusions are done to replace blood lost during surgery or due to a serious injury. A transfusion also may be done if your body can't make blood properly because of an illness. Each year, almost 1 million British need a blood transfusion.
B7.17 Plenary Lesson summary: Decide whether the following statements are true or false : False True 3: There are five blood types X, A, B, O and AB ? False True 2: A red blood cell has no nucleus, a large surface area and haemoglobin ? False True 1: Your blood cells are mad in the soft marrow of the long bones ? oxygen microbes cells capillary Blood contains a number of specialised _____ which move around the entire ___________ network. Red blood cells have a large surface area and contains haemoglobin which binds _________. Other blood cells are part of our immune system which fights invading _____ like bacteria and viruses On average, there are about 4,000,000 red blood cells in every 1 cm 3 of blood in the human body. Their role is to transport oxygen form the lungs to every cell in the human body. Populations that live at altitude have many more blood cells per cm3 because the air contains less oxygen as you climb in altitude . How Science Works: Friday 21 October 2011 Research into different human blood types and how these types are inherited form our mother and farther. Preparing for the next lesson:
B7.18 Blood groups and transfusions Decide whether the following statements are true or false: <ul><li>Lesson objectives: </li></ul><ul><li>Understand that there are four different blood type in humans A, B, O and AB </li></ul><ul><li>Understand how your blood types is inherited from your mother and father </li></ul>Friday 21 October 2011 First activity: Give three reasons why a person may undergo a blood transfusion ? PLTS Independent enquirers Creative thinkers Reflective learners Team workers Effective participators Self managers We will focus on t Literacy: Blood, circulation, heart, blood cells, veins, arteries, capillaries, red blood cells, plasma, white blood cells, clotting, platelets, nutrients and hormones. Numeracy: There are 5 litres of blood in each human and each single millilitre of blood contains about 4,000,000 red blood cells. Do the maths and that’s many billions of red blood cell. On average they last about 90 days from their manufacture in the bone marrow.
Decide whether the following statements are true or false: Extension questions: 1: Do you know your own blood type ? 2: Find out which is the most common blood type in your class ? 3: Blood type AB is the most rare, with only 3% of the population having this blood type. Why should humans that have AB blood regularly donate ? 4: Why is donated blood only store for about 100 days ? 5: Why are adults only allowed to donate blood in the UK and work out how many transfusion are done in the UK over one week ? Know this: a: Know that there are four different blood types found in humans b: Know how your inherit your blood types form your mother and father. Friday 21 October 2011 Introduction: There are just four human blood types: Blood type A, B, AB and O. During a blood transfusion, blood donors and recipients are matched. If blood types are not matched during a blood transfusion between recipients and donors then fatal blood clotting can occur. Over 9000 blood transfusions are done daily in the UK. Your blood type (A, B or O) is inherited. Blood types is determined by a single gene. The gene for blood type has three different alleles. Allele IA – red blood cells have A antigens (surface proteins) Allele IB – red cells have B antigens (surface proteins) Allele IO – red cell lack any antigens on their surface B7.18 Blood groups and transfusions
Key concepts B7.18 a Look at the photograph and information and answer all the questions: Explain why two AB parents cannot give birth to a child with type O blood ? Work out the possible blood types of the children of a father with type O blood (OO) and a mother with type AB blood ? The ABO blood group is based on the presence of two major antigens on red blood A and B. A person's red blood cell contains one of four antigen combinations as a result of inheritance: only A, only B, both A and B, or neither A nor B. A person with only antigen A has type A blood. A person with only antigen B has type B blood. An individual with both antigen A and B has type AB blood. A person with neither antigen A nor B has type O blood. Thus, all humans have one of four possible ABO blood types - A, B, AB, or O . Human blood types
Key concepts B7.18 b Look at the photograph and information and answer all the questions: T Why are schools no longer allowed to do this practical where a pupil can find out his or her blood group ? Why is a control run as the same time as the other tests to find out the person's blood type ? During a blood transfusion, if two different blood types are mixed together, the blood cells may begin to clump together in the blood vessels, causing a potentially fatal situation. Therefore, it is important that blood types be matched before blood transfusions take place. In an emergency, type O blood can be given because it is most likely to be accepted by all blood types. However, there is still a risk involved . Testing blood sample to find your blood type Take a sample of blood Place sample of blood on slide Add Anti-A, Anti-B and Anti-O and wait 5 minutes In this example the human has blood type O. Anti-O coagulated (clumped) with the human blood indicating a positive result
Key concepts B7.18 c Look at the photograph and information and answer all the questions: During a blood transfusion, if two different blood types are mixed together, the blood cells may begin to clump together in the blood vessels, causing a potentially fatal situation. Therefore, it is important that blood types be matched before blood transfusions take place. In an emergency, type O blood can be given because it is most likely to be accepted by all blood types. However, there is still a risk involved. Why are humans with blood type AB called the universal recipients ? Why are humans with blood type O called universal donors ? Look opposite left, why has the nurse indicated that Timmy is blood type O ? Human blood types
B7.18 Plenary Lesson summary: Decide whether the following statements are true or false : False True 3: Humans can also receive blood form dogs and horses ? False True 2: A person with AB type blood is called a universal donor ? False True 1: O is the most common blood type found in humans ? gene four matched alleles There are _______ human blood types, A, B, AB and O. Blood type is controlled by one single _____ inherited from your mother and father. There are three _______ for this gene A, B and O. During a blood transfusion, blood types are ________ between donor and recipient. Before AIDs and knowledge of other blood borne infections, a common practical that all students did was do a blood test that identified which blood group each student had. Since 1985, schools were banned from doing this practical reduced the risk of infection form one student to another. How Science Works: Friday 21 October 2011 Research into the anatomy of the heart ad the flow of blood through the double circulation of the human body. Preparing for the next lesson:
Decide whether the following statements are true or false: Friday 21 October 2011 First activity: Explain what is mean by a double circulation and explain why muti-cellular organisms like mammals require a transport system ? PLTS Independent enquirers Creative thinkers Reflective learners Team workers Effective participators Self managers We will focus on t B7.19 The heart <ul><li>Lesson objectives: </li></ul><ul><li>Understand the anatomy of the heart </li></ul><ul><li>Understand how blood flows through the heart and the body through a double circulation </li></ul>Literacy: Circulation, heart, atria, valves, ventricles, tendons, blood cells, veins, arteries, capillaries, red blood cells, plasma, white blood cells, clotting, platelets, nutrients and hormones. Numeracy: The human heart is an amazing example of bio-engineering. Beating 70 times a minute it pumps a staggering 50,000 litres of blood every day. Over a lifetime that an amazing 1500,000,000 or 1.5 trillion litres of blood
Friday 21 October 2011 B7.19 The heart Introduction: The heart, a four chambered pump which pumps blood to the lungs, picking up oxygen and excreting carbon dioxide and then to the body delivering oxygen and nutrients to every respiring cell, via a network of arteries, veins and capillaries. The ventricles create sufficient pressure by squeezing to send blood either to the lungs (right ventricle) or the rest of the body (left ventricle) A number of valves between the connecting chambers stops any unwanted backflow of blood. Extension questions: 1: Which arteries supply the heart with its own blood supply ? 2: There are three types of muscle. Which type of muscle is found in the heart ? 3: Explain why the heart atria are very thin walled and the heart ventricles are very thick walled ? 4: Name the artery that leaves the left ventricle and supply blood to the body 5: Name the vein that brings blood from the body to the right atria ? 6: Explain how you could take a resting pulse of a patient ? Know this: a: Know the structure and function of the heart. b: Know that humans have a double circulation.
Look at the photograph and information and answer all the questions: The cardiovascular system’s role is to transport useful substance like oxygen and nutrients to respiring cells whilst removing waste substances like carbon dioxide and urea. Your blood also transports hormones produced by the endocrine glands, for example adrenalin. White blood cells, antibodies and platelets are also transported by the blood and help prevent infection caused by viruses and bacteria. The heart pumps blood to which organs to pick up oxygen ? Arteries take blood away from the heart...which blood tubes take blood towards the heart ? Explain how red blood cells are adapted to carry oxygen around the entire circulatory system ? Red blood cell Cardiovascular system Key concepts B7.19 a
Key concepts B7.19 b Look at the photograph and information and answer all the questions: The human heart’s function is to pump blood to the lungs (RA, RV) and to the the body (LA, LV). Valves between the four chambers (Atria and Ventricles) open and close to prevent blood from being forced backed when the ventricles contract. The difference in blood pressure in the arties and veins allows blood to flow around the body. What is unique about the pulmonary artery and the pulmonary vein ? True or false if you remove a small piece of heart muscle it would twitch or contract about 72 times a minute ? Explain why the left ventricle is far large and muscular when compared to the hearts right ventricle ? Anatomy of the heart
The heart as a pump Decide whether the following statements are true or false: Introduction: Friday 21 October 2011 RA contracts RV contracts Blood from LA to LV LV contracts Look at the photograph and information and answer all the questions: Look the diagram of the heart cycle above and the corresponding activity in the vagal nerve. What is happening during a) the QRS peak b) the T wave ? At rest in an average adult, the heart beat approximately 72 times a minute. Each beat is controlled by the vagus nerve. This nerve controls the contraction and relation of the hearts atria and ventricles B7.19 c
Look at the photograph and information and answer all the questions: Blood flows along major routes supplying the key organs or organs systems of the body. How much blood each area or organ receive depends on their activity and size. Blood flow to key muscle areas can change according to whether your exercising or not. One organ that receives a constant supply of blood regardless of anything else is the brain How would you expect blood flow to the skeletal muscle to change from resting to participating in a 800 metre race ? Explain why blood flow to the brain and heart is never compromised in favour of other organs like the muscle system or intestines ? Explain why you suffer stomach cramps if you exercise shortly after eating a meal ? Anatomy of human circulation Key concepts B7.19 d
Plenary Lesson summary: cells closed oxygen four All mammals have a _____ double circulatory system that deliver ______ and nutrients a high pressure to all respiring _____. The blood is pumped to the lungs and then to the entire body by a _____ chambered heart The blood pressure in your arteries is about 120 mm of Hg (mercury), where as the blood pressure in your veins is about 80 mm of Hg. The difference (120 – 80) is the pressure that forces blood from your heart through the arteries, capillaries and veins and back to your heart How Science Works: Friday 21 October 2011 Please look into blood and its components and the three types of blood tubes arteries, veins and capillaries. Preparing for the next lesson: B7.19 Decide whether the following statements are true or false : False True 3: The heart is a six chambered pump ? False True 2: There are two types of blood tubes arteries and veins ? False True 1: The hemacrit describe the amount of plasma in whole blood ?
B7.20 Valves and tissue fluid Decide whether the following statements are true or false: <ul><li>Lesson objectives: </li></ul><ul><li>Understand the function of the heart valves found inside the heart </li></ul><ul><li>Understand the role of the tissue fluid and what role it plays is transporting oxygen and nutrients to respiring cells and tissues. </li></ul>Friday 21 October 2011 First activity: Arteries carry blood away form the heart at high [pressure and veins carry blood towards the heart at low pressure. Explain why arteries are much thicker walled when compared to veins. Literacy: Tissue exchange, diffusion, pressure, osmosis, diffusion, circulation, blood, heat, capillaries, interstitial fluid, red blood cells, oxygen, nutrients lymph system. Numeracy: The pressure in arteries which move blood from the heart is far greater than the pressure found in the veins which moves blood toward to heart. This pressure difference forces blood from the heart around the body and back into the heart. BLP Resilience Resourcefulness Reciprocity Reflectiveness We will focus on t.
Friday 21 October 2011 B7.20 Valves and tissue fluid Extension questions: 1: What feature of a humans veins helps blood return to the heart against gravity and at low pressure ? 2: Give one function of the valves found inside the heart ? 3: Do red blood cells leave capillaries to deliver oxygen to respiring cells and tissues ? 4: Give two substances that tissue fluid contains ? 5: name two substances that return to the blood system from the respiring tissue ? 6: Explain why the capillary network is almost 40,000 km long ? Know this: a: Know the role of the heart valves b: Know the role of the tissue fluid in transporting oxygen and nutrients form blood to respiring cells Introduction: The double circulation in humans is important because without it, blood flow would be too slow to provide enough oxygen for the body’s respiring cells. When blood enters the capillary network formation of tissue fluid which escapes through the capillary wall (one cell thick) takes oxygen and dissolved nutrients to the cells and tissues. Tiny gaps in the capillary wall and hydrostatic pressure also help tissue fluid move form inside the capillaries to cells and tissues. Some of the tissue fluid returns back to the capillary by osmosis, but not all due to the hydrostatic pressure gradient which works against tissue fluid return. Excess fluid is returned via the lymph system
Look at the photograph and information and answer all the questions: Capillaries have a small diameter allowing only one red blood cell through at a time. Blood flows very slowly through your capillaries. The capillaries are extremely thin walled, which allows oxygen and interstitial fluid to diffuse to the tissue bed. Waste products like urea and CO 2 can pass from the cells back to the capillary. The tissue fluid contains nutrients.. What would these nutrients be if you analysed a small sample of tissue fluid ? How is CO 2 transported from cells back to the lungs where it is excreted. Explain why capillaries have tiny sphincter muscles at key points and what is there role and when are these used ? Capillary bed Cell Key concepts B7.20 a
Key concepts B7.20 b Look at the photograph and information and answer all the questions: T What is the difference between diffusion and ultra filtration ? Explain how tissue fluid a) moves from the capillary to the tissue and b) from the tissue to the capillaries ? When blood enters the capillaries, tissue fluid escapes through the capillary wall (one cell thick) taking oxygen and dissolved nutrients to the cells and tissues. Red blood cells are too large to pass through the tiny gaps in the capillaries. Some of the tissue fluid returns back to the capillaries by osmosis, but not all due to the hydrostatic pressure gradient which works against tissue fluid return. Excess fluid is returned via the lymph system . Exchange at the capillary bed ultrafiltration diffusion net outflow net inflow 15 mmHg 28mm Hg diffusion osmosis Hydrostatic pressure venule end Arteriole end osmosis
Look at the photograph and information and answer all the questions: The pressure difference between systole and diastole is 40 mm Hg in a healthy adult. For an athlete what would it be like ? The formation of interstitial or tissue fluid aids the delivery to cells of oxygen and nutrients (and other substances) and the removal of waste. Tissue fluid is formed from plasma components that can pass by diffusion through the capillary wall and into the surrounding tissue bed. Tiny gaps in the capillary walls allow this to happen. Hydrostatic pressure cause by the heart beating also helps drive this tissue fluid out. Look at the graph below left…explain how blood pressure changes from the left ventricle and aorta to the capillaries and then the veins and finally the right atria. Also sketch what the same graph for someone who has advance arterial sclerosis and high blood pressure ? Key concepts B7.20 c
Key concepts B7.20 d Look at the photograph and information and answer all the questions: The heart does not work alone to deliver oxygen and nutrients to the entire body. Blood is pumped around a highly complex system of blood vessels measuring over 40,000 km in the average human. There are three types of blood vessels: Arteries, Veins and Capillaries. Arteries carry blood at the highest pressure away from the heart and therefore have the thickest elastic muscle wall of all of the different types of blood tubes. All arteries carry blood away from the heart, but do all arteries carry oxygenate blood ? Veins carry blood at low pressure (80 mm Hg) and arteries carry blood at high pressure (120 mm Hg). Explain the differences in their anatomy ? Capillaries are single celled narrow tubes that allow oxygen and nutrients to reach all cells. Explain why they are one cell thick ? Elastic fibres Outer wall Valve Thin muscle Outer wall Thick muscle Elastic fibres Capillaries Artery Vein
B7.20 Plenary Lesson summary: lymph tissue oxygen glucose Capillaries allow ______ fluid to leave transporting ________, dissolved nutrients like _________ and other small molecules. This tissue fluid then return to the blood by diffusion and osmosis and the ______ system The lymph system is an incredible important additional circulation system that trickles back tissue fluid to the jugular vein and also cleans the blood. It also goes through the lymph glands which are home to many immune cells (white blood cells) How Science Works: Friday 21 October 2011 Research into how cells respire provide energy for life and how glucose and oxygen combine forming energy, water and carbon dioxide. Preparing for the next lesson: Decide whether the following statements are true or false : False True 3: The lymph system also cleans the tissue fluid ? False True 2: Red blood cells carry oxygen directly to cells by leave the capillary network ? False True 1: Capillaries are thick walled to withstand high blood pressures ?
B7.21 Energy for life Decide whether the following statements are true or false: <ul><li>Lesson objectives: </li></ul><ul><li>Understand how respiration releases energy by respiring glucose with oxygen </li></ul><ul><li>Understand where respiration occurs inside cells </li></ul><ul><li>Understand the difference between anaerobic and anaerobic respiration </li></ul>Friday 21 October 2011 First activity: The formulae for glucose is C 6 H 12 O 6 , for oxygen O 2 , for water H 2 O and for carbon dioxide CO 2 . Write and balance a symbol equation that describes cellular respiration ? Literacy: Respiration, glucose, oxygen, carbon dioxide, water, energy, mitochondria, breathing, cellular energy, anaerobic and aerobic. Numeracy: For every one molecule of glucose respired, 6 molecules of oxygen are required producing 6 molecules of water and 6 molecules of carbon dioxide. PLTS Independent enquirers Creative thinkers Reflective learners Team workers Effective participators Self managers We will focus on t
B7.21 Staying alive Decide whether the following statements are true or false: Introduction: Your body and its trillions of cells have to respire to stay alive. Cellular respiration is the release of energy when glucose from your diet reacts with oxygen to form water and carbon dioxide. Most of the energy you require comes form aerobic respiration, however when sprinting or doing very hard work some of the energy that your muscles require can come form anaerobic respiration. Even without oxygen for short periods, cell can respire glucose producing carbon dioxide, lactic acid and small amount of cellular energy Extension questions: 1: What two gases does the blood transport around the body ? 2: Where does respiration occur inside the human cell ? 3: Explain how oxygen moves form the lung surface into the blood binding a red blood cell ? 4: Write a word equation for aerobic and anaerobic cellular respiration ? 5: During anaerobic respiration what causes the burning sensation in muscles ? Know this: a: Know that during cellular respiration energy is released. b: Know that the waste products of respiration are carbon dioxide and water Friday 21 October 2011
B7.21 a Look at the photograph and information and answer all the questions: We all need energy to function and we get this energy from the foods we eat. The most efficient way for cells to harvest energy stored in food is through cellular respiration, a pathway for the production of adenosine tri-phosphate (ATP). ATP, a high energy molecule, is expended by working cells. Cellular respiration occurs in both plant and animal cells. Explain why mitochondria are found in both plant and animal cells ? Where would you expect to find most mitochondria and why in a) the woody stem or growing bud of a tree ? Do plants respire a) during sun light hours, b) at night only or c) all day long ? 6H 2 O 6CO 2 C 6 H 12 O 6 6O 2 Respiration in animals and plants Equation for respiration 6O 2 (g) + C 6 H 12 O 6 (s) CO 2 (g) + 6H 2 O (l) Key concepts
B7.21 b Look at the photograph and information and answer all the questions: Respiration occurs in every cell inside the mitochondria. It’s the release of energy from the breakdown of glucose using oxygen from air, forming water and carbon dioxide. In animals, 90% of the energy available from ingested food is used for every day activities like muscle contraction, transporting chemicals, absorbing food and maintaining a constant body temperature. If you compared the levels of carbon dioxide in exhaled or inhaled air...which would have the highest concentration ? The cell part which respires glucose is called the mitochondria. Would you expect to find more of these cell parts in muscle cells ? One molecule of glucose is respired with 6 molecules of oxygen...how many molecules of carbon dioxide and water are formed ? C 6 H 12 O 6 + 6O 2 6H 2 O + 6CO 2 + energy Key concepts Cellular respiration C 6 H 12 O 6 6O 2 6CO 2 6H 2 O Cells + energy substrates products
B7.21 Plenary Lesson summary: Decide whether the following statements are true or false : False True 3: Glucose is respired using carbon dioxide gas ? False True 2: Aerobic respiration produces lactic acids in the muscles ? False True 1: Mitochondria where respiration occurs are not found in plant cells ? anaerobic energy aerobic oxygen Respiration means the release of _______ from food. The chemical process involved works most efficiently if ______ is used. Just like a fire needs an oxygen supply to burn the fuel, so _______ respiration needs oxygen. Without oxygen the respiration does not release all the energy and is called ______ respiration. There is increasing evidence that World record beating sprinters like Usain Bolt have great numbers of mitochondria in their muscle cells compared to other sprinters. This gives them an advantage or natural ability to produce more energy that is used by the muscle cells during contraction when the leg muscles are propelling the runner forward.. How Science Works: Friday 21 October 2011 Research into anaerobic respiration and coping with lactic acid in the muscle cells. Preparing for the next lesson: