4.2 Organisation 4.2.1 Principles of organisation This section is covered at KS3, so be omitted, depending on your students, or taught as an introduction to 4.1 Cell biology. Organ systems associated with the specification are the Digestive, Circulatory, Respiratory, Nervous, Endocrine, Reproductive and Excretory Systems. Spec ref. Summary of the specification content Learning outcomes What most candidates should be able to do Suggested timing (hours) Opportunities to develop scientific communication skills Opportunities to apply practical and enquiry skills Self/peer assessment opportunities and resources Reference to past questions that indicate success 4.2.1.1 Organisational hierarchy. Cells are the building blocks of living organisms. A tissue is a group of cells with a similar structure and function. Organs are groups of tissues working together. Organs are organised into organ systems. An organism is made up of several organ systems. Explain the cell, tissue, organ, organ system and organism, and be able to give examples of each. Have an understanding of the size and scale of cells, tissues, organs, organ systems and organisms. Describe the main systems in the human body and their functions. 0.5 Recap KS3 work on organisation using models and images of the human body and organs. Prepare a set of cards with images of different body organs and ask pupils to arrange the cards into organ systems. What is the function of each organ within its system? Produce a flow diagram showing organisation in large organisms and relate to size. Using models. Critically evaluating models to identify those features which are effectively represented and those which are not. Torso, models or images of systems, models or images of organs showing different tissues.
Iodine reagent is to be used to test for starch every 30 seconds. Temperature must be controlled by use of a water bath or electric heater. and give explanations for the results. reaction using raw data and graphs. Draw conclusions and give explanations for the results. 4.2.2.1 Human digestive enzymes Enzymes in the digestive system chemically digest food into small, soluble molecules that can be absorbed. Names of enzymes with substrates, products and sites of production. Bile is made by the liver and stored in the gall bladder. It helps in the digestion of fats by neutralising acid from the stomach and emulsifying fats. Explain why need to be digested into small, soluble molecules. Describe the three types of enzymes involved in digestion, including the names of the substrates, products and where the enzymes are produced. Explain how bile in the digestion of fats. Interpret graphs to determine the optimum temperature or pH for an enzyme. 2 Observe a model for digestion using popper beads to illustrate large molecules being broken into smaller ones. Introduce the names of the three groups of digestive enzymes, what they digest and the products formed. Present the information in a table. Discuss the role of bile and demonstrate the action of washing up liquid on fats. Demonstrate the effect of bile salts on the rate of digestion of milk using a pH indicator. Use bead Investigate the action of amylase on starch using a model gut or interpret the results using the computer simulation. Watch the demos and discuss the outcomes. Explain why pH is measured to indicate the rate of fat digestion. Model: Strings of popper beads. gut: amylase solution, starch solution, cellulose tubing, beaker, iodine solution, Benedict’s solution, test tubes, spotting tile, waterbath. Demo: large trough of water, greasy frying pan, washing up liquid, tube of water and olive oil Demo: two tubes full cream milk, sodium carbonate solution,
Different enzymes work best at different temperatures and pH values. Required practical: Food tests. Use qualitative reagents to test for a of carbohydrates, lipids and proteins. To include: Benedict’s test for sugars; iodine test for starch; and Biuret reagent for protein. Carry out other enzyme controlled investigations as appropriate. Calculate the rate of enzyme controlled reactions. Interpret the results from enzyme controlled reactions. a model or large poster of the digestive system identify where each type of enzyme and bile is produced. Add labels to the digestive system diagram to show where the different enzymes and bile are produced. Optional investigations or use computer simulations and interpret and explain the results: investigate the optimum pH values for pepsin and trypsin. investigate the effect of temperature on amylase activity. Use the BBC activity the digestive system. Make a life size of the digestive system. Role play – What happens to food as it along the digestive system? Investigate the optimum pH values for pepsin and trypsin enzymes. Relate the results to their sites of action in the digestive system. Investigate the effect of temperature on amylase activity – measure time taken for starch to disappear. Plot results and find optimum temperature for amylase. Plot and interpret graphs about enzyme activity; determine optimal temperatures and pH values. phenolphthalein or UI solution, lipase solution, +/- washing up liquid and timer. pH: Pepsin solution, trypsin solution, buffer solutions at different pH values, UI strips, egg white suspension, test tubes, timers and goggles. Amylase: amylase solution, starch solution, test tubes, water baths at different temperatures, thermometers, glass rods, spotting tiles, iodine solution, timers, goggles.
4.2.2.4 Coronary heart disease. material builds up in coronary arteries reducing blood flow to the heart muscle. Stents can be used to keep the coronary arteries open. Statins reduce cholesterol levels, so fatty material is deposited more slowly. Faulty heart valves can be replaced with biological or mechanical ones. Heart failure can be treated with a heart and lung transplant. Artificial hearts can be used whilst waiting for a transplant, or to allow the heart to rest and recover. Describe problems associated with the and explain how they can be treated. Evaluate the use of drugs, mechanical devices and transplants to treat heart problems, including religious and ethical issues. 1 Watch video clip about coronary heart disease. Discuss the different of heart problems that can occur and how they are treated coronary arteries, heart attack, faulty valves, hole in the heart, drugs, transplants, artificial hearts and replacement valves. Produce a report or PowerPoint presentation. Observe illustrations of artificial hearts and replacement valves. Demonstrate effect of blockage in tube on rate of flow. Observe video of heart and lung transplant. BBC animation and quiz about heart disease. Research the first heart transplant. Demo: calculate the rate of water flow through tubing. Evaluate the use of models to represent blocked arteries. Artificial heart and valves if available otherwise show illustrations. Demo: rigid, transparent tubing – one left open and the other partially blocked with wax, funnel, measured volumes of water, timer.
4.2.2.3 Blood. Blood is a tissue consisting of plasma, red blood cells, white blood cells and platelets. Plasma transports dissolved chemicals and proteins around the body. Red blood cells transport oxygen attached to haemoglobin. White blood cells help to protect the body against infection. Platelets are fragments of cells involved in blood clotting. Describe the four main components of Explain how each component is adapted for its function. Identify pictures of the different blood cells. 1 Discuss the functions of blood and describe the four main components of blood. Draw and label diagrams of red blood cells, white blood cells and platelets. Watch BBC lesson about blood with animations (see resources). Produce models of red blood cells, white blood cells and platelets. Produce a Mind map to explain the composition of blood and describe the functions of plasma, red blood cells, white blood cells and platelets. Write a word equation for the reaction of oxygen with haemoglobin. Observe prepared blood smears, or use Compare the size and number of red and white blood cells. Microscopes, prepared slides or bio-viewers. 4.2.2.5 4.2.2.6 Health issues and effect of lifestyle on non-communicable diseases Explain how diet, stress and life situations can affect physical and mental health. 1 Discuss factors that can affect health and how to lead a healthy lifestyle. out research using textbooks and the internet and Carry out research. Adverts:
Health is the state of physical and mental well-being. Factors such as diet, stress and life situations can have a serious effect on physical and mental health. Diseases are causes of ill health. Different diseases may interact: defects in the immune system increase the chance of catching an infectious disease. infections can trigger cancers. Immune reactions can trigger allergies. Physical ill-health can lead to depression and mental illness. Various risk factors are linked to some Give examples of communicable and diseases. Describe examples of how diseases may interact. Describe the effects of diet, smoking, alcohol and exercise on health. Explain how and why the Government encourages people to lead a healthy lifestyle. Give risk factors associated with cardiovascular disease, Type 2 diabetes, lung diseases and cancers. write a report on the effects of diet, stress, smoking, alcohol and exercise on health, to include risk factors for specific diseases. Analyse data health risks and diseases. Carry out a survey of lifestyle habits. Watch the adverts about smoking, alcohol and diet. Analyse the message they are sending and suggest why. Ask what advice do they give and how effective they are and why. Brainstorm the human and financial cost of these diseases on individuals, communities, nations and globally. Role-play a doctor and patient discussing the benefits and difficulties of one lifestyle change, eg smoking, alcohol, diet or exercise. Collect, present and analyse data about health risks and diseases, looking for correlations. Measure height and weight to calculate BMI. Calculate BMI and evaluate the use of this type of measurement.
Xylem tissue is composed of hollow tubes strengthened with lignin. Phloem tissue transports dissolved sugars from the leaves to other parts of the plant. The movement of food through phloem is called translocation. Phloem cells have pores in their end walls for movement of cell sap. enters leaves via stomata; light is absorbed by chlorophyll in leaves; dissolved sugars are transported from the leaves in the phloem to other parts of the plant. 4.1.3.3 4.1.3.3 Active transport. Active transport involves the movement of a substance against a concentration gradient and requires energy from respiration. Mineral ions can be absorbed by active transport into plant Define the term ‘active transport’. Describe where active transport occurs in humans and plants and what is transported. Explain why active transport requires energy. 0.5 Recap diffusion and osmosis. Compare them with active transport. Produce a comparison table. Introduce active transport as absorption against the concentration gradient. Discuss when this might be useful. Research where active transport occurs in plants and Investigate the effect of oxygen availability on the growth of plants. (Could be amended to investigate need for nitrate and magnesium ions, links with 4.3.3.1). Observe results in later lessons. Use of a
root hairs from very dilute solutions in the soil. can be absorbed by active transport from the gut into the blood. Explain how active transport enables cells to absorb ions from very dilute solutions. Explain the relationship between active transport and oxygen supply and numbers of mitochondria in cells. humans and label these on diagrams with notes. Observe a video or pictures of plants growing in soil and in hydroponic solutions. Suggest why farmers and gardeners turn the soil and hydroponic solutions must be kept aerated. Use the Nuffield activity. Students can carry out a similar investigation to demonstrate the need for oxygen. Observe images of the mitochondria in root hair cells and cells lining the small intestine. Relate to active transport. Observe a computer simulation of active transport. Oxygen: gas jars with lids, glass tubes, fresh and boiled water to make mineral ion solution(s), black paper.