2)+Structure+and+function+of+living+organism

a) Levels of organisation b) Cell structure c) Biological molecules d) Movement of substances into and out of cells e) Nutrition f) Respiration g) Gas exchange h) Transport i) Excretion j) Coordination and response
 * Section 2: Structures and functions in living organisms**

a) Levels of organisation

//Students will be assessed on their ability to:// 2.1 describe the levels of organisation within organisms: organelles, cells, tissues, organs and systems.

b) Cell structure

//Students will be assessed on their ability to:// 2.2 recognise cell structures, including the nucleus, cytoplasm, cell membrane, cell wall, chloroplast and vacuole 2.3 describe the functions of the nucleus, cytoplasm, cell membrane, cell wall, chloroplast and vacuole 2.4 describe the differences between plant and animal cells.

workbook: homework:

c) Biological molecules

//Students will be assessed on their ability to:// 2.5 recall the chemical elements present in carbohydrates, proteins and lipids (fats and oils) 2.6 describe the structure of carbohydrates, proteins and lipids as large molecules made up from smaller basic units: starch and glycogen from simple sugar; protein from amino acids; lipid from fatty acids and glycerol 2.7 describe the tests for glucose and starch 2.8 understand the role of enzymes as biological catalysts in metabolic reactions 2.9 understand how the functioning of enzymes can be affected by changes in temperature **2.10 understand how the functioning of enzymes can be affected by changes in pH** 2.11 describe how to carry out simple controlled experiments to illustrate how enzyme activity can be affected by changes in temperature



d) Movement of substances into and out of cells

//Students will be assessed on their ability to:// 2.12 recall simple definitions of diffusion, osmosis and active transport 2.13 understand that movement of substances into and out of cells can be by diffusion, osmosis and active transport **2.14 understand the importance in plants of turgid cells as a means of support** 2.15 understand the factors that affect the rate of movement of substances into and out of cells to include the effects of surface area to volume ratio, temperature and concentration gradient 2.16 describe simple experiments on diffusion and osmosis using living and non-living systems.

e) Nutrition

//Students will be assessed on their ability to:// Flowering plants 2.17 describe the process of photosynthesis and understand its importance in conversion of light energy to chemical energy 2.18 recall the word equation and the balanced chemical symbol equation for photosynthesis 2.19 understand how carbon dioxide concentration, light intensity and temperature affect the rate of photosynthesis 2.20 explain how the structure of the leaf is adapted for photosynthesis 2.21 recall that plants require mineral ions for growth and that magnesium ions are needed for chlorophyll and nitrate ions are needed for amino acids 2.22 describe simple controlled experiments to investigate photosynthesis, showing the evolution of oxygen from a water plant, the production of starch and the requirements of light, carbon dioxide and chlorophyll

Humans **2.23 understand that a balanced diet should include appropriate proportions of carbohydrate, protein, lipid, vitamins, minerals, water and dietary fibre** 2.24 recall sources and describe functions of carbohydrate, protein, lipid (fats and oils), vitamins A, C and D, and the mineral ions calcium and iron, water and dietary fibre as components of the diet **2.25 understand that energy requirements vary with activity levels, age and pregnancy** 2.26 recognise the structures of the human alimentary canal and describe in outline the functions of the mouth, oesophagus, stomach, small intestine, large intestine, and pancreas 2.27 understand the processes of ingestion, digestion, absorption, assimilation and egestion 2.28 explain how and why food is moved through the gut by peristalsis 2.29 understand the role of digestive enzymes to include 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 2.30 recall that bile is produced by the liver and stored in the gall bladder, and understand the role of bile in neutralising stomach acid and emulsifying lipids 2.31 explain how the structure of a villus helps absorption of the products of digestion in the small intestine **2.32 recall how to carry out a simple experiment to determine the energy content in a food sample**

f) Respiration

//Students will be assessed on their ability to:// 2.33 recall that the process of respiration releases energy in living organisms http://purchon.com/wordpress/biology/?page_id=206 2.34 describe the differences between aerobic and anaerobic respiration TEST yourself: __ [] __ 2.35 recall the word equation and the balanced chemical symbol equation for aerobic respiration in living organisms 2.36 recall the word equation for anaerobic respiration in plants and in animals **2.37 describe simple controlled experiments to demonstrate the evolution of carbon dioxide and heat from respiring seeds or other suitable living organisms** http://www.phschool.com/science/biology_place/labbench/lab5/design.html

g) Gas exchange (Chapter 3 of Edexcel IGCSE Biology)

//Students will be assessed on their ability to:// 2.38 understand the role of diffusion in gas exchange. []

Flowering plants 2.39 understand gas exchange (of carbon dioxide and oxygen) in relation to respiration and photosynthesis 2.40 understand that respiration continues during the day and night, but that the net exchange of carbon dioxide and oxygen depends on the intensity of light 2.41 explain how the structure of the leaf is adapted for gas exchange 2.42 describe the role of stomata in gas exchange 2.43 describe simple controlled experiments to investigate the effect of light on net gas exchange from a leaf, using hydrogen-carbonate indicator

Humans 2.44 describe the structure of the thorax, including the ribs, intercostal muscles, diaphragm, trachea, bronchi, bronchioles, alveoli and pleural membranes [] pneumothorax (punctured lung) - interesting reading: http://en.wikipedia.org/wiki/Punctured_lung Or watch this if in the UK (it's Youtube) http://www.youtube.com/watch?v=i-sZzZ4TMnY 2.45 understand the role of the intercostal muscles and the diaphragm, in ventilation [] 2.46 explain how alveoli are adapted for gas exchange by diffusion between air in the lungs and blood in capillaries [] 2.47 understand the biological consequences of smoking in relation to the lungs and the circulatory system 2.48 describe a simple experiment to investigate the effect of exercise on breathing in humans. h) Transport //Students will be assessed on their ability to://  2.49 understand why simple, unicellular organisms can rely on diffusion for movement of substances in and out of the cell

__** Xylem, Phloem & Root hair cells **__ 2.50 understand the need for a transport system in multicellular organisms Flowering plants 2.51 describe the role of phloem in transporting sucrose and amino acids between the leaves and other parts of the plant http://highered.mcgraw-hill.com/sites/9834092339/student_view0/chapter38/animation_-_phloem_loading.html 2.52 describe the role of the xylem in transporting water and mineral salts from the roots to other parts of the plant 2.53 explain how water is absorbed by root hair cells

Trees are freaking awesome!!: see link below.. a bit higher level but very interesting and good revision of the key concepts involved in transport in plants: http://www.youtube.com/watch?v=BickMFHAZR0 __** Transpiration **__ 2.54 recall that transpiration is the evaporation of water from the surface of a plant 2.55 explain how the rate of transpiration is affected by changes in humidity, wind speed, temperature and light intensity 2.56 describe experiments that investigate the role of environmental factors in determining the rate of transpiration from a leafy shoot

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Use the following link: http://www.mhhe.com/biosci/genbio/virtual_labs/BL_10/BL_10.html and answer the questions below....
 * 1) 1. Run the experiment with all 4 of the available plants in each condition. (You can click and drag the plants and equipment to the front table)
 * 2) 2. Click on the timer to run the experiment
 * 3) 3. Record the results in the table below.
 * |||||||| Transpiration Rate (ml per hr)  ||
 * Plant || Lamp || Heater || Fan || Lab conditions ||
 * 1 ||  ||   ||   ||   ||
 * 2 ||  ||   ||   ||   ||
 * 3 ||  ||   ||   ||   ||
 * 4 ||  ||   ||   ||   ||

When you have finished collecting results, answer these questions: http://www.mhhe.com/biosci/genbio/virtual_labs/BL_10/BL_10.html http://www.sciencemag.org/site/feature/misc/webfeat/vis2005/show/trans.html
 * 1) 1. Which plant had the highest rate of transpiration overall?
 * 2) 2. What qualities does this plant have that might explain this?
 * 3) 3. Which condition created the highest transpiration rate in the plants?
 * 4) 4. Can you explain why it has this effect?
 * 5) 5. Draw the potometer and label the diagram to explain how it measures the rate of transpiration.
 * 6) 6. If you carried out this experiment in the lab, what variables would you control to make sure the results were reliable and valid?

Humans 2.57 recall the composition of the blood: red blood cells, white blood cells, platelets and plasma 2.58 understand the role of plasma in the transport of carbon dioxide, digested food, urea, hormones and heat energy 2.59 describe the adaptations of red blood cells for the transport of oxygen, including shape, structure and the presence of haemoglobin 2.60 describe how the immune system responds to disease using white blood cells, illustrated by phagocytes ingesting pathogens and lymphocytes releasing antibodies specific to the pathogen **2.61 understand that vaccination results in the manufacture of memory cells, which enables future antibody production to the pathogen to occur sooner, faster and in greater quantity** **2.62 recall that platelets are involved in blood clotting, which prevents blood loss and the entry of microorganisms** 2.63 describe the structure of the heart and how it functions http://www.wisc-online.com/objects/ViewObject.aspx?ID=AP12504 2.64 understand that the heart rate changes during exercise and under the influence of adrenaline 2.65 describe the structure of arteries, veins and capillaries and understand their roles 2.66 recall the general plan of the circulation system to include the blood vessels to and from the heart, the lungs, the liver and the kidneys i) Excretion i) excretion

//Students will be assessed on their ability to://

Flowering plants 2.67 recall the origin of carbon dioxide and oxygen as waste products of metabolism and their loss from the stomata of a leaf

Humans 2.67 recall that the lungs, kidneys and skin are organs of excretion 2.68 understand how the kidney carries out its roles of excretion and of osmoregulation 2.69 describe the structure of the urinary system, including the kidneys, ureters, bladder and urethra 2.70 describe the structure of a nephron, to include Bowman’s capsule and glomerulus, convoluted tubules, loop of Henlé and collecting duct 2.71 describe ultrafiltration in the Bowman’s capsule and the composition of the glomerular filtrate 2.72 understand that water is reabsorbed into the blood from the collecting duct 2.73 understand that selective reabsorption of glucose occurs at the proximal convoluted tubule 2.74 describe the role of ADH in regulating the water content of the blood 2.75 recall that urine contains water, urea and salts

//Students will be assessed on their ability to:// 2.76 understand that organisms are able to respond to changes in their environment 2.77 understand that homeostasis is the maintenance of a constant internal environment and that body water content and body temperature are both examples of homeostasis 2.78 understand that a coordinated response requires a stimulus, a receptor and an effector

= Flowering plants = 2.79 understand that plants respond to stimuli

The external environment is changing all the time and in order for an organism to survive in their environment they must be able to respond to these changes.

There are environmental changes that are familiar to us and are obvious to spot: Daily changes · light (day) and dark (night) · temperature, warmer (day) and colder (night)

e.g. photosynthesis only in light sunflowers turning to face sun some flowers close at night

Seasonal Changes · day length – longer days in summer and shorter during the day · temperature changes – summers are usually hotter than winter · water availability – water may be scarce in summer (drought) but it can also be scarce in winter if it freezes.

e.g. leaves changing colour and falling off due to lack of water and sunlight (so no photosynthesis).  Flowering for reproduction

Other environmental changes may be subtle and we may not notice them: Gas concentration · CO2 and O2 concentration may fluctuate during a 24-hour period due to different rates of photosynthesis and respiration. · Chemicals in the air, soil and water. E.g. if there are not enough nitrates in the soil, the plant may not grow properly. (Nitrates needed to make amino acids à proteins - à growth and repair).



Cambridge book: Read page 102 & 103 Edexcel book: Read Chapter 12 P135 (Answer Q's 1-3 on P. 142 to check understanding)

1. What three things are essential for an organism to respond to an external stimulus?

2. What is the main difference between how plants and animals detect and respond to stimuli?

3. Which part of a shoot is sensitive to light and where does the response to light take place?

4. What is the only type of communication system in a plant?

5. How are hormones transported around a plant?

2.80 describe the geotropic responses of roots and stems 2.81 describe positive phototropism of stems

__Early Experiments of Shoot Growth__ 1. Experiment – cut tip off shoot, place a block of gelatine on stump and replace tip. Shine light on plant from one side. Result – it still bends towards the light Conclusion – was not nervous transmission as it had been cut and the message was still transmitted. Could be a hormone that can still diffuse through the jelly

2. Experiment – cut tip off shoot, place a slip of metal on stump and replace tip. Shine light on plant from one side.

Result – nothing happens – it does not bend Conclusion – hormone cannot travel through the metal, diffusion is stopped.

3. Experiment – slips of metal place half way across shoot and light shone from one side and then the other.

Result – when metal is same side as light the shoot bends. When metal is on ‘dark’ side the shoot does not bend Conclusion – when metal and light on same side the hormone can still move down the ‘dark’ side and cause the shoot to bend. When metal and light are on opposite sides, the hormones cannot travel down the ‘dark’ side and so shoot does not bend.

4. Experiment – Cut tips off and place on half the stump. Shine light from one side. Result – Conclusion –

It was concluded from these experiments that chemicals controlled shoot elongation. The chemicals were given the group name of **auxins**.

__Summary__ 1. Auxin produced in tip of shoot 2. Water soluble and diffuses though shoot 3. Auxin cause elongation of cells which promotes growth 4. Auxin travels to the darker side of the shoot to promote growth causing shoot to bend toward light

Predict what would occur in the following experiments

Assume the light is shining from the right for the experiments below!

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Humans 2.82 describe how responses can be controlled by nervous or by hormonal communication and understand the differences between the two systems 2.83 recall that the central nervous system consists of the brain and spinal cord and is linked to sense organs by nerves 2.84 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 2.85 describe the structure and functioning of a simple reflex arc illustrated by the withdrawal of a finger from a hot object 2.86 describe the structure and function of the eye as a receptor **2.87 understand the function of the eye in focusing near and distant objects, and in responding to changes in light intensity** **2.88 describe the role of the skin in temperature regulation, with reference to sweating, vasoconstriction and vasodilation** 2.89 understand the sources, roles and effects of the following hormones: ADH, adrenaline, insulin, testosterone, progesterone and oestrogen