This document outlines a biology course curriculum covering various topics related to photosynthesis, respiration, circulation, genetics, and more over 12 lessons. It then provides details on one specific lesson regarding breathing and gas exchange, including objectives, key concepts, and assessment questions. The lesson focuses on how the lungs, alveoli, and blood vessels facilitate the rapid exchange of oxygen and carbon dioxide between inhaled air and blood.

1. 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

3. B7.22 Breathing and gaseous exchange Decide whether the following statements are true or false: Introduction: Gas exchange at the respiratory membrane is rapid due to several factors: 1: The large surface area available for diffusion due to the high number of alveoli in the lungs. There are between 300-500 million alveoli with an internal surface area approximately equivalent to the size of a tennis court. 2: The distance for diffusion is short as the respiratory membrane is thin 3: The vast network of pulmonary capillaries that surrounds the alveoli. 4: The small diameter of the pulmonary capillaries means that the red blood cells have to "squeeze" through. 5:The red blood cells therefore come into contact with the capillary wall so respiratory gases do not have to travel through a lot of plasma to reach them. Extension questions: 1: Explain the role of the following parts of the respiratory system during the breathing cycle a) ribs and inter-costal muscles b) wind pipe c) diaphragm and d) alveoli ? 2: Why is the average lung capacity in males larger when compared to the average lung capacity in females ? 3: Why are the lungs a) moist b) supplied with a good supply c) large surface area ? 4: by what process does oxygen move form a) outside into the lungs and b) form the lung space across the alveoli and into the blood ? Know this: a: Know how the lungs function. b: Know about gaseous exchange between the lung space and blood through alveoli tissue. Friday 21 October 2011

4. Key concepts B7.22 a Look at the photograph and information and answer all the questions: Explain the role of the following a) wind pipe b) ribs c) intercostal muscles and d) diaphragm ? How does faster and deeper breathing help increase the rate of oxygen deliver to cells when doing exercises ? On average, you breathe about 15 times per minute, or more than 21,000 breaths each day. A sheet of muscle called the diaphragm, which forms the bottom wall of the chest cavity, plays a key role in breathing. You inhale when your diaphragm and rib muscles contract, which expands your chest cavity. This action increases the volume of your lungs, resulting in reduced air pressure within the alveoli. Since air tends to move from an area of higher pressure to an area of lower pressure, air rushes in through the nose or mouth and fills the alveoli. Anatomy of lungs

5. B7.21 b Look at the photograph and information and answer all the questions: Your lungs exchange oxygen for carbon dioxide between the alveoli tissue and your red blood cells. At rest, your lungs expand and contract about 15 times every minute. The breathing rate can increase depending on the oxygen demand for your entire body. Your inter-costal muscles, ribcage and diaphragm work together to help your lungs inhale and exhale during gaseous exchange. The world record for ‘holding breath’ underwater is just under 15 minutes. Why did the record holder keep very still when attempting this record ? The alveoli tissue exchanges oxygen for carbon dioxide...explain what this process of gas molecules moving is called ? List three features which help oxygen diffuse from the lung space across the alveoli and into the blood ? Key concepts Anatomy of lungs

6. B7.22 Plenary Lesson summary: Decide whether the following statements are true or false : False True 3: On average you inhale about 21,000 litres or air a day ? False True 2: Alveoli are thin, moist and large in surface area ? False True 1: Air breathed out contains higher levels of oxygen when compare to air ? downwards inhalation rib pressure Breathing consists of two phases, _________ and expiration. During inspiration, the diaphragm moves _________ and the ____ cage move up and out increasing the volume of the chest cavity. This increase of volume lowers the air ________ in the alveoli to below atmospheric pressure. This pressure difference causes air to rush in. We all know how oxygen is carries in the blood but what about carbon dioxide. Out of the carbon dioxide released from respiring cells, 7% dissolves into the plasma, 23% binds to haemoglobin and 70% is carried as bicarbonate ions in the plasma. Carbon dioxide created by respiring cells diffuses into the blood plasma and then into the red blood cells, where most of it is converted to bicarbonate ions How Science Works: Friday 21 October 2011 Research into the effect of exercise in the human body. Preparing for the next lesson:

9. B7.23 a Look at the photograph and information and answer all the questions: Fitness is a measure of how well your body and its key organ systems perform. Athletes require ‘total fitness’ so that they can win and excel at their sport. Athletes train the cardiovascular and respiratory systems to all work efficiently together to supply the oxygen and nutrients to your muscles during a race. They also focus on good nutrition with a vitamin and mineral rich low fat diet. Explain how regular exercise improve the efficiency of the cardiovascular system ? Give three types of exercise that would improve upper body strength ? Explain why professional athletes make sure they have a balanced diet and avoid alcohol, smoking or using any drugs ? Respiratory system Cardiovascular system Muscle strength, skill and flexibility Body fat Total fitness in humans Key concepts

10. B7.23 b Look at the photograph and information and answer all the questions: Athletes require their key organ systems to work together so that they can exercise and play their sport. Fitness is a measure of how well you body performs. Athletes require ‘total fitness’ so that they can win and excel at their sport. The nervous, cardiovascular, respiratory and skeletal-muscle system all work together provide all the parts of a winning performance. Why does blood flow to your leg muscles start to increase when you start walking or running ? Explain why athletes will work on their overall fitness and make sure they have good nutrition when preparing for a race ? The picture opposite left shows a fatty plaque narrowing a major artery...how might this plaque affect blood flow around the body ? Key concepts

11. Key concepts B7.23 c Look at the photograph and information and answer all the questions: Look at the graph left. How many seconds did a) the exercise last for b) the athlete went into oxygen debt and c) the time taken for the oxygen debt to be repaid ? Explain why even at rest, oxygen uptake is above 0 dm 3 /min ? The expression "lactic acid" is used by athletes to describe pain felt during exhaustive exercise like the 400 metres. When large amounts of energy is required, the muscles can produce it anaerobically for short periods of time, however the end product is lactic acid which can accumulate and reduce the pH of the muscle tissue. This lowering of pH is what athletes register as ‘burn’ The resulting ‘oxygen debt’ and accumulated lactic acid has to be repaid and cleared by breathing rates remain high even when exercise has stopped 0 10 20 30 40 50 60 70 rest exercise recovery 5.0 4.0 3.0 2.0 1.0 0.0 oxygen uptake (dm 3 /min) Aerobic respiration Oxygen debt Repaying the oxygen debt resting rate fully recovered

12. B7.23 Plenary Lesson summary: Decide whether the following statements are true or false : False True 3: Athlete train to build up their tolerance to lactic acid forming in the muscles ? False True 2: Lactic acid can raise the pH of muscle when it begins to accumulate ? False True 1: A long distance runner will rarely require anaerobic respiration ? pH lactic oxygen debt Toxic _______ acid will accumulated in muscles that are working hard and have outstripped the supply of ________ carried by red blood cells. After a short period of anaerobic respiration this oxygen ______ must be repaid and the lactic acid cleared so the ____ of the muscle tissue returns to normal. During a 400 metre race, runners will begin to use the lactic acid system and respire glucose anaerobically for about a further 35 seconds. As lactic acid accumulates the pH of the muscle system can become very acidic. In fact the low pH actually starts to damage muscle tissue and you feel this damage as muscle soreness. How Science Works: Friday 21 October 2011 Research into the role of ATP adenosine tri-phosphate and how its used by the body as the currency of energy. Preparing for the next lesson:

14. Decide whether the following statements are true or false: Introduction: Aerobic respiration takes place inside the cell. All cells need an energy supply to carry out their functions. Glucose and oxygen are transported by the blood in the circulatory system. Parts of the cell called the mitochondria is the actual location for aerobic respiration. The energy release during respiration is stored inside the cell by a chemical called ATP. When energy is needed, by for example a contracting muscle cell, the ATP molecule is broken down releasing energy. Your leg muscles store about 10 to 15 seconds worth of ATP, so after that time during exhaustive exercise, your muscles start to respire anaerobically. Extension questions: 1: Give an example when anaerobic respiration will taken place inside the human body ? 2: During a fox hunt, if you measured the pH of the fox's leg muscles over the course of the hunt what would you see ? 3: Describe how ATP is produced inside cells ? 4: Why is ATP called the energy currency of the cell ? 5: Explain why you find more ATP producing mitochondria inside muscle cells when compared to other cells like skin cells ? Know this: a: Know that respiration produces ATP a short term store of chemical energy. b: Know that ATP when broken down releases energy inside the cell. Friday 21 October 2011 B7.24 Respiration and ATP

15. Key concepts B7.24 a Look at the photograph and information and answer all the questions: What does ATP stand for and how do muscles use ATP to do useful work ? How is ATP produced in cells ? How do muscles contract ATP is a chemical molecules that is a short term energy store and is used by cells and tissue to do useful work like contracting muscle fibres. In a muscle cell, the ATP molecules and the energy it contains in its molecular structure is used to allow the muscle fibre to contract and do work. ATP and calcium ions bind onto the muscle fibre. The ATP molecule is then converted into ADP and the energy released is used by the muscle fibre to do work. The ADP molecules then leaves the biding site leaving the muscle fibre to repeat the process.

16. Key concepts B7.24 b Look at the photograph and information and answer all the questions: ATP is a chemical molecule that serves as the primary energy currency of the cell. ATP is the most widely distributed high-energy compound within the human body. This ubiquitous molecule is “used to build complex molecules, contract muscles and generate electricity in nerves. All foodstuffs of living things, produce ATP, which in turn powers virtually every activity of the cell and organism. Look at the diagram opposite left. What happens to ATP when it forms ADP and energy ? List three processed that the body requires ATP for ? Where does ATP found in the cell come from ? ATP…the ultimate nano-machine !

17. B7.24 Plenary Lesson summary: Decide whether the following statements are true or false : False True 3: ATP is made using the energy released by respiring glucose ? False True 2: Muscle cells contain less ATP when compared to skin cells ? False True 1: ATP contains three phosphate groups ? energy glucose steady work Muscle contraction needs a _________ supply of ATP. When ATP is broken down forming ADP, it releases energy which can be used to do _____. ADP is then remade using respiration where __________ and oxygen are combined. ATP is sometimes called the _____ currency of the cell. Adenosine tri-phosphate or ATP contains three phosphate groups. When it is formed by using the energy from cells respiring glucose, the phosphate – phosphate bond stores the chemical energy. When the phosphate is broken apart that energy is used to do useful work like build new molecules, contracting muscle fibres and send electrical impulses along nerve fibres. How Science Works: Friday 21 October 2011 Research into the human skeletal muscle system and the role of the skeleton in the human body Preparing for the next lesson:

19. Decide whether the following statements are true or false: Introduction: We all have an internal skeleton which support, protects and moves our body. This makes us vertebrates. Around the skeleton is a complex system of different tissues including muscle, ligaments and tendons which hold your bones together and also provide the force required to move your skeletal muscle system. The skeleton in additional to supporting protecting and moving us also acts a a a store of mineral s, and site where blood cells are made. Extension questions: 1: List three function of a human skeleton ? 2: What is the role of a) cartilage b) tendons and c) ligaments ? 3: Describe the main differences between a ball and socket joint and a hinged joint ? 4: What dietary mineral is used to make bones ? 5: Give two sources of this mineral ? 6: Explain why a runner will have a higher bone density when compared to an average human being ? Know this: a: Know the role of the skeletal muscle system. b: Know the anatomy of bones. Friday 21 October 2011 B7.25 The skeleton

20. Key concepts B7.25 a Look at the photograph and information and answer all the questions: What roles does the a) skull b) ribs and c) femur have ? Describe how exercise (running) changes bones in adults ? The human skeleton consists of both fused and individual bones held in place by a series of ligaments, tendons, muscles and cartilage. It serves as a scaffold which moves the body, supports key organs, anchors muscles, and protects organs such as the brain, lungs and heart against physical shock. The largest bone in the body is the femur in the upper leg, and the smallest is the stapes bone in the middle ear. In an adult, the skeleton comprises around 14% of the total body weight and half of this weight is water The human skeleton

21. Key concepts B7.25 b Look at the photograph and information and answer all the questions: The main misconception about bones, is that they are made up of dead tissue. This is not true, they have cells, nerves, blood vessels and pain receptors. Bone is made from organic and inorganic material and cells which all turn over at a fairly rapid rate. Inside the soft marrow of bones is where the blood cells are made. Bones are about as strong as cast iron but one third of the weight. Why is a high strength to weight ration important ? Why do bones require a blood supply ? What mineral is used to make the inorganic matrix that give bones their immense strength ? Anatomy of bones Blood supply Cartilage Cavity (marrow) Cartilage Compact bone Spongy bone

22. B7.25 Plenary Lesson summary: Decide whether the following statements are true or false : False True 3: Bone is made from living tissue and a matrix of calcium ? False True 2: Adults have more bones than newborns ? False True 1: The largest bone in the human body is the tibia ? living exercise blood bone The skeleton is not just made of non _________ matter. Its tissues such as ______, cartilage and marrow are made from living cells with their own _________ supply. Bone is continuously broken down and rebuilt and can change when a person does weight bearing ________ over long periods of time . Newborn babies have 270 bones in their body but by the time they become an adult, the number shrink to 206 because many bones making up the skull and the spine fuse together as the body grows and becomes older. Over half our bones are located in our feet (52 bones) and hands (54 bones) How Science Works: Friday 21 October 2011 Research into the types of joints found in the human skeleton and look into the anatomy of the synovial joint. Preparing for the next lesson:

25. Key concepts Look at the photograph and information and answer all the questions: What is the role of a) the cartilage and b) the synovial fluid in this knee joint ? What tissue a) keeps the femur and the tibia in place and b) what tissue attaches muscle to bone ? The knee joint is the largest movable joint and consists of 4 bones (femur, fibula, tibia and patella and an extensive network of ligaments and muscles. The main movements of the knee joint occur between the femur, patella and tibia. Each are covered in cartilage which is an extremely hard and smooth substance designed to decrease friction as movement occurs between the bones. To further reduce friction the joint is filled with an oily fluid called the synovial fluid. B7.26 a Inside a synovial joint (knee)

26. Key concepts Look at the photograph and information and answer all the questions: Name three pair of muscles that work together to move part of the skeleton ? Why do muscles work in antagonistic pair to move parts of the skeleton ? B7.26 b Muscles can only contract, therefore all movement is produced using a pair of muscles working antagonistically. You have a pair of muscles for each movement you can make. both muscles move by contracting. When one of the muscles contracts, it moves you one way. When the other muscle contracts, it moves you the other way. Obviously, in many cases you actually have a lot more muscles working in a lot of different combinations. But the basic way they move you is always by the muscle contracting and releasing.

27. Key concepts B7.26 c Look at the photograph and information and answer all the questions: Describe the main differences between compact and spongy bone ? What cells are made in the soft marrow of adult bones ? The functions of bone are many and include a) structural support for the mechanical action of soft tissues, such as the contraction of muscles and the expansion of lungs b) protection of soft organs tissues, for example the brain is protected by the skull c) provision of a protective site for specialized tissues such as the blood-forming system and d) a mineral reservoir, whereby the endocrine system regulates the level of calcium and phosphate in the circulating body fluids Inside bones Spongy bone Arteries Central canal Compact bone veins Fibrous layer

28. B7.26 Plenary Lesson summary: Decide whether the following statements are true or false : False True 3: The knee is an example of a bally and socket joint ? False True 2: The cartilage and synovial fluids reduce friction in a joint ? False True 1: Muscles are attached to bone by ligaments ? joint pairs forearm biceps Muscle work in ________ to move parts of the skeletal system, for example the ________ and triceps work together to move the ________. Muscles must work in pairs because they can only ________ around a moving joint. The knee joint is the most commonly injured joint in humans. It is a weight bearing joint that support about 80% of your body weight. With its four bones, many tendons and ligaments, over use in sport can lead to injury and sometimes permanent damage. The cruciate ligament runs horizontally and keeps the joint assembly stable. This ligament can be damaged when sportspeople stop and turn quickly. How Science Works: Friday 21 October 2011 Research into sport injuries and using RICE (rest ice elevation and compression) to minimise the impact of an injury on the skeletal muscle system. Preparing for the next lesson:

30. Decide whether the following statements are true or false: Introduction: The skeletal muscle system is an amazing example of bioengineering, however there is a limit to the force that joints can with stand when a person plays a sport or exercises. Common injuries include muscle sprains, joint dislocations, torn ligaments and torn tendons. Sports that require a person to stop and turn (football, netball, tennis and rugby) are particularly impacting on the knee joint and many of the ligaments that stabilise the knee. RICE (rest, ice , elevation and compression) is used to minimise the damage after an injury to a muscle, joint, tendon or ligament. Extension questions: 1: Explain why sports like football and netball are bad news for knee joints ? 2: List two other common types of joint injury associated with over exercising or a playing a sport ? 3: How does rest in between exercise help prevent over sue injuries ? 4: Explain why its important to follow the principles of RICE when you have injured yourself ? 5: Explain the role of a physiotherapist following an injury ? Know this: A: Know how excessive use causes an injury. b: Know how rest, ice, elevation and compression help minimise damage that follows a sports injury. Friday 21 October 2011 B7.27 Sport injuries

31. Key concepts B7.27 a Look at the photograph and information and answer all the questions: RICE stands for : Rest, Ice, Compression and Elevation. You want to start by resting your injured area and take a few days off from your workouts. The ice part is crucial to reduce pain and inflammation. Compression also really helps to keep your area stable (especially with a sprain) and can also reduce swelling. Elevation of the injured area can also reduce swelling by helping excess fluid drain back toward the heart. Describe the main symptoms of a) a sprain b) a torn ligament and c) a dislocation ? Why are footballers particularly at risk of knee injuries ? Describe a set of exercises that a physiotherapist may give you to strengthen the knee joint following an injury ?

32. B7.27 b Look at the photograph and information and answer all the questions: A athlete requires an efficient and healthy skeletal – muscle system to move their body during a race. Muscles move bones at a joint. A tendon connects the muscle to the bone. Ligaments connect bone to bone and stabilise a joint as it moves. Muscles cannot push, they can only pull or contract so they all work in antagonist pairs. Joint wear can occur as we age or for other reasons like rheumatoid arthritis. We have 206 bones that make up our adult skeleton. What mineral is bone made from ? Explain why athletes stretch, warm up and warm down before and after a race ? The picture opposite left shows a replacement knee joint. Explain how a knee joint can wear over time ? Key concepts The skeletal muscle system Knee replacement surgery

33. Key concepts Look at the photograph and information and answer all the questions: Explain why a fractured hip is much more serious when compared to a fracture of the upper arm ? Explain why doctors recommend increasing dairy intake following a bone fracture ? B7.27 c Bones are incredibly strong but can fracture when an excessive load force above the bones ‘breaking point’ is applied. Take the hip, for example. Most often, the fracture occurs in the upper part of the femur. You can also have more than one type of fracture at a time. A transcervical fracture is a break across the neck of the femur. This type of fracture can interrupt blood flow to the joint. An inter-trochanteric fracture is a break down through the top of the femur. A sub-trochanteric fracture is a break across the shaft of the femur Fracture of the skeletal system

34. B7.27 Plenary Lesson summary: Decide whether the following statements are true or false : False True 3: Gentle exercise three days after an injury can help joint recovery ? False True 2: Ice helps reduce swelling which can prolong recovery time ? False True 1: A dislocation is when bone slips out of its joint ? recovery sprains tendons ice Athletes can suffer form dislocations ______, torn ligaments and ______ when they overuse their skeletal muscle system. Rest, _____, elevation and compression can help minimise joint damage and aid _______. A physiotherapist not only treats you when you have injured your skeletal muscle system, but can also teach you to do exercises that will strengthen a joint which helps prevent injury. A physiotherapist can also teach you how to warm up and down properly before beginning to exercise. How Science Works: Friday 21 October 2011 Research into how fitness programs are designed to improve a persons fitness over time. Preparing for the next lesson:

36. Athletes training Decide whether the following statements are true or false: Introduction: We all know that regular exercise is an important part of a health lifestyle. A training program done by a doctor or a personal trainer is designed to improve the fitness of a novice who is want to get fit or the performance times of an elite athlete. Doctors may check factors like weight, blood pressure, heart rate, and lifestyle risk factors like smoking, diet and family history before they design a specific training program that will safely allow a person to become fitter. Extension questions: 1: Give three pieces of medical history that should be checked and recorded by doctors before a person begins a fitness program ? 2: Explain why blood pressure, resting heart rate and weight should be checked over the course of the training program ? 3: Explain why a fitness program will look at diet, reducing risk factors like smoking and alcohol intake as well as encouraging exercise ? 4: Explain why resting heart rate or blood pressure is not a indicator of a person’s fitness ? Know this: a: Know the basic concepts behind a fitness program. b: Know that training programs can help an athlete to perform better and become more competitive. Friday 21 October 2011 B7.28

37. Key concepts B7.28 a Look at the photograph and information and answer all the questions: Describe the difference between a training program for a relatively fit 45 year old male and an unfit 25 year old female ? Doctors when designing a fitness program for the obese will also monitor a patients blood pressure and heart rate. Why is this important to do ? Any fitness program should include a range of exercises that will increase a) Mobility… mobility is defined as the capacity of joints and joint chains for flexion and extension. S trength…strength is defined as a muscle or muscle group’s ability to develop mechanical force. Endurance…endurance is defined as the capacity of the athlete to resist fatigue during applications of work over periods of time. Endurance depends on the maximum aerobic and anaerobic powers and the ability with which they can be utilized.

38. Key concepts Look at the photograph and information and answer all the questions: Measuring overall fitness may require a number of different tests. Tests to measure heart rate, blood pressure, strength, endurance and suppleness can all be recorded and compared over the duration of a fitness training program. No one test will give you sufficient information to indicate how fit a person is. Why is information on a persons resting heart rate not sufficient information to determine overall fitness ? How would you measure a) strength and b) suppleness of an individual ? Why should elite athletes also consider their diets when trying to improve their overall fitness levels ? B7.28 b

39. B7.28 Plenary Lesson summary: Decide whether the following statements are true or false : False True 3: Footballer require endurance, strength and suppleness to play their game well ? False True 2: Improving endurance is important for long distance runners ? False True 1: Resting heart rate can be used to determine a persons overall fitness ? doctor endurance heart blood If a person is following a ________ program, both a personal trainer and a _________ will monitor their progress. During the program, a person's mobility, ___________ and strength will worked on by the trainer with doctors checking their health by looking a _______ pressure and _______ rate An elite athlete will have a whole team of trainers, physiotherapists and doctors behind them so they can compete and win Gold at events like the Olympics. Without a very precise and coordinated training program, elite athletes would fail to be competitive at the highest level. How Science Works: Friday 21 October 2011 Revise the 28 lessons in this module and prepare for an end of unit test. Preparing for the next lesson: