2 Structure and functions in living organisms
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(a) Level of organisation
2.1
Describe the levels of organisation in organisms: organelles, cells, tissues, organs and systems.
(b) Cell structure
2.2Cell structures
Describe cell structures, including the nucleus, cytoplasm, cell membrane, cell wall, mitochondria, chloroplasts, ribosomes and vacuole.
2.3Cell structure functions
Describe the functions of the nucleus, cytoplasm, cell membrane, cell wall, mitochondria, chloroplasts, ribosomes and vacuole.
2.4Plant and animal cell structure
Know the similarities and differences in the structure of plant and animal cells.
2.5BCell differentiation
Explain the importance of cell differentiation in the development of specialised cells.
2.6BStem cells in medicine
Understand the advantages and disadvantages of using stem cells in medicine.
(c) Biological molecules
2.7Elements in biological molecules
Identify the chemical elements present in carbohydrates, proteins and lipids (fats and oils).
2.8Biological molecule structure
Describe the structure of carbohydrates, proteins and lipids as large molecules made up from smaller basic units: starch and glycogen from simple sugars, protein from amino acids, and lipid from fatty acids and glycerol.
2.9Food tests
Practical: investigate food samples for the presence of glucose, starch, protein and fat.
2.10Enzymes as biological catalysts
Understand the role of enzymes as biological catalysts in metabolic reactions.
2.11Temperature and enzyme function
Understand how temperature changes can affect enzyme function, including changes to the shape of active site.
2.12Enzyme activity practical
Practical: investigate how enzyme activity can be affected by changes in temperature.
2.13pH and enzyme function
Understand how enzyme function can be affected by changes in pH altering the active site.
2.14BEffect of pH on enzyme activity practical
Practical: investigate how enzyme activity can be affected by changes in pH.
(d) Movement of substances into and out of cells
2.15Cell transport processes
Understand the processes of diffusion, osmosis and active transport by which substances move into and out of cells.
2.16Factors affecting cell transport
Understand how factors affect the rate of movement of substances into and out of cells, including the effects of surface area to volume ratio, distance, temperature and concentration gradient.
2.17Diffusion and osmosis practical
Practical: investigate diffusion and osmosis using living and non-living systems.
(e) Nutrition
2.18Photosynthesis and energy conversion
Understand the process of photosynthesis and its importance in the conversion of light energy to chemical energy.
2.19Photosynthesis equations
Know the word equation and the balanced chemical symbol equation for photosynthesis.
2.20Factors affecting photosynthesis
Understand how varying carbon dioxide concentration, light intensity and temperature affect the rate of photosynthesis.
2.21Leaf adaptations for photosynthesis
Describe the structure of the leaf and explain how it is adapted for photosynthesis.
2.22Mineral ions for plant growth
Understand that plants require mineral ions for growth, and that magnesium ions are needed for chlorophyll and nitrate ions are needed for amino acids.
2.23Photosynthesis practical
Practical: investigate photosynthesis, showing the evolution of oxygen from a water plant, the production of starch and the requirements of light, carbon dioxide and chlorophyll.
2.24Balanced diet
Understand that a balanced diet should include appropriate proportions of carbohydrate, protein, lipid, vitamins, minerals, water and dietary fibre.
2.25Dietary sources and functions
Identify the sources and describe the functions of carbohydrate, protein, lipid (fats and oils), vitamins A, C and D, the mineral ions calcium and iron, water and dietary fibre as components of the diet.
2.26Energy requirements
Understand how energy requirements vary with activity levels, age and pregnancy.
2.27Alimentary canal structure and function
Describe the structure and function of the human alimentary canal, including the mouth, oesophagus, stomach, small intestine (duodenum and ileum), large intestine (colon and rectum) and pancreas.
2.28Peristalsis
Understand how food is moved through the gut by peristalsis.
2.29Digestive enzymes
Understand the role of digestive enzymes, including the digestion of starch to glucose by amylase and maltase, the digestion of proteins to amino acids by proteases and the digestion of lipids to fatty acids and glycerol by lipases.
2.30Bile production and storage
Understand that bile is produced by the liver and stored in the gall bladder.
2.31Roles of bile
Understand the role of bile in neutralising stomach acid and emulsifying lipids.
2.32Small intestine adaptations for absorption
Understand how the small intestine is adapted for absorption, including the structure of a villus.
2.33BFood energy practical
Practical: investigate the energy content in a food sample.
(f) Respiration
2.34Respiration and ATP
Understand how the process of respiration produces ATP in living organisms.
2.35ATP provides energy for cells
Know that ATP provides energy for cells.
2.36Aerobic and anaerobic respiration
Describe the differences between aerobic and anaerobic respiration.
2.37Aerobic respiration equations
Know the word equation and the balanced chemical symbol equation for aerobic respiration in living organisms.
2.38Anaerobic respiration equations
Know the word equation for anaerobic respiration in plants and in animals.
2.39Respiration products practical
Practical: investigate the evolution of carbon dioxide and heat from respiring seeds or other suitable living organisms.
(g) Gas exchange
2.40BDiffusion in gas exchange
Understand the role of diffusion in gas exchange.
2.41BGas exchange in respiration and photosynthesis
Understand gas exchange (of carbon dioxide and oxygen) in relation to respiration and photosynthesis.
2.42BLeaf adaptations for gas exchange
Understand how the structure of the leaf is adapted for gas exchange.
2.43BStomata in gas exchange
Describe the role of stomata in gas exchange.
2.44BLight intensity and net gas exchange
Understand how respiration continues during the day and night, but that the net exchange of carbon dioxide and oxygen depends on the intensity of light.
2.45BLight and leaf gas exchange practical
Practical: investigate the effect of light on net gas exchange from a leaf, using hydrogen-carbonate indicator.
2.46Thorax structure
Describe the structure of the thorax, including the ribs, intercostal muscles, diaphragm, trachea, bronchi, bronchioles, alveoli and pleural membranes.
2.47Ventilation muscles
Understand the role of the intercostal muscles and the diaphragm in ventilation.
2.48Alveoli adaptations
Explain how alveoli are adapted for gas exchange by diffusion between air in the lungs and blood in capillaries.
2.49Biological consequences of smoking
Understand the biological consequences of smoking in relation to the lungs and the circulatory system, including coronary heart disease.
2.50Ventilation practical
Practical: investigate breathing in humans, including the release of carbon dioxide and the effect of exercise.
(h) Transport
2.51Diffusion in unicellular organisms
Understand why simple, unicellular organisms can rely on diffusion for movement of substances in and out of the cell.
2.52Transport systems
Understand the need for a transport system in multicellular organisms.
2.53Phloem transport
Describe the role of phloem in transporting sucrose and amino acids between the leaves and other parts of the plant.
2.54Xylem transport
Describe the role of xylem in transporting water and mineral ions from the roots to other parts of the plant.
2.55BWater absorption by root hair cells
Understand how water is absorbed by root hair cells.
2.56BTranspiration
Understand that transpiration is the evaporation of water from the surface of a plant.
2.57BFactors affecting transpiration rate
Understand how the rate of transpiration is affected by changes in humidity, wind speed, temperature and light intensity.
2.58BTranspiration practical
Practical: investigate the role of environmental factors in determining the rate of transpiration from a leafy shoot.
2.59Blood composition
Describe the composition of the blood: red blood cells, white blood cells, platelets and plasma.
2.60Transport by blood plasma
Understand the role of plasma in the transport of carbon dioxide, digested food, urea, hormones and heat energy.
2.61Red blood cell adaptations
Understand how adaptations of red blood cells make them suitable for the transport of oxygen, including shape, the absence of a nucleus and the presence of haemoglobin.
2.62Immune response to disease
Understand how the immune system responds to disease using white blood cells, illustrated by phagocytes ingesting pathogens and lymphocytes releasing antibodies specific to the pathogen.
2.63BVaccination and memory cells
Understand how vaccination results in the manufacture of memory cells, which enable future antibody production to the pathogen to occur sooner, faster and in greater quantity.
2.64BBlood clotting
Understand how platelets are involved in blood clotting, which prevents blood loss and the entry of micro-organisms.
2.65The heart and how it functions
Describe the structure of the heart and how it functions.
2.66Heart rate changes
Explain how the heart rate changes during exercise and under the influence of adrenaline.
2.67Coronary heart disease risk factors
Understand how factors may increase the risk of developing coronary heart disease.
2.68Arteries, veins and capillaries
Understand how the structure of arteries, veins and capillaries relate to their function.
2.69Circulatory system structure
Understand the general structure of the circulation system, including the blood vessels to and from the heart and lungs, liver and kidneys.
(i) Excretion
2.70Metabolic waste gases
Understand the origin of carbon dioxide and oxygen as waste products of metabolism and their loss from the stomata of a leaf.
2.71Excretory products of lungs, kidneys and skin
Know the excretory products of the lungs, kidneys and skin (organs of excretion).
2.72BKidney excretion and osmoregulation
Understand how the kidney carries out its roles of excretion and osmoregulation.
2.73BUrinary system structure
Describe the structure of the urinary system, including the kidneys, ureters, bladder and urethra.
2.74BNephron structure
Describe the structure of a nephron, including the Bowman’s capsule and glomerulus, convoluted tubules, loop of Henle and collecting duct.
2.75BUltrafiltration
Describe ultrafiltration in the Bowman’s capsule and the composition of the glomerular filtrate.
2.76BWater reabsorption from the collecting duct
Understand how water is reabsorbed into the blood from the collecting duct.
2.77BSelective reabsorption of glucose
Understand why selective reabsorption of glucose occurs at the proximal convoluted tubule.
2.78BADH and blood water content
Describe the role of ADH in regulating the water content of the blood.
2.79BUrine composition
Understand that urine contains water, urea and ions.
(j) Co-ordination and response
2.80Responses to environmental change
Understand how organisms are able to respond to changes in their environment.
2.81Homeostasis
Understand that homeostasis is the maintenance of a constant internal environment, and that body water content and body temperature are both examples of homeostasis.
2.82Stimulus, receptor and effector
Understand that a co-ordinated response requires a stimulus, a receptor and an effector.
2.83Plant responses to stimuli
Understand that plants respond to stimuli.
2.84Tropic responses
Describe the geotropic and phototropic responses of roots and stems.
2.85Auxin and phototropism
Understand the role of auxin in the phototropic response of stems.
2.86Nervous and hormonal communication
Describe how nervous and hormonal communication control responses and understand the differences between the two systems.
2.87Central nervous system
Understand that the central nervous system consists of the brain and spinal cord and is linked to sense organs by nerves.
2.88Nerve impulses and rapid responses
Understand that stimulation of receptors in the sense organs sends electrical impulses along nerves into and out of the central nervous system, resulting in rapid responses.
2.89Neurotransmitters at synapses
Understand the role of neurotransmitters at synapses.
2.90Simple reflex arc
Describe the structure and functioning of a simple reflex arc illustrated by the withdrawal of a finger from a hot object.
2.91Eye structure and function
Describe the structure and function of the eye as a receptor.
2.92Eye focusing and light responses
Understand the function of the eye in focusing on near and distant objects, and in responding to changes in light intensity.
2.93Skin and temperature regulation
Describe the role of the skin in temperature regulation, with reference to sweating, vasoconstriction and vasodilation.
2.94Adrenaline, insulin and reproductive hormones
Understand the sources, roles and effects of the following hormones: adrenaline, insulin, testosterone, progesterone and oestrogen.
2.95BADH, FSH and LH
Understand the sources, roles and effects of the following hormones: ADH, FSH and LH.