Thursday, March 14, 2019

COMBINED LESSON C1-C2 Introduction to Chemistry IGCSE

C1-C2 Combined Chemistry Lesson

A combined resource with 4 lessons containing:
1. Chem syllabus 2017-2018
2. Apparatus List (with worksheet)
3. Lesson on Matter (with extra resources, and homework sheet)
4. Lesson Experimental Techniques (with quiz and homework page)
5. Lesson on Paper Chromatography (with homework page and extra resources)

If you are starting the iGCSE course this is a good one to cover the first chapters with 4 lessons covering all the previous topics mentioned in the last few posts.

Find the lesson here 



Sunday, July 30, 2017

The New IGCSE CIE Combined Science 0653 Syllabus

International General Certificate of Secondary Education (IGCSE) for the Cambridge International Education for Combined Science (0653) 2019-2021

  • CIE
  • Combined Science (0653)
  • Chemistry
  • Biology
  • Physics

The entire specification can be found on the CIE website here.

I have created a nine slide PowerPoint summary explaining the new CIE Combined Science 0653 syllabus. The slides give an overview of syllabus, an explanation of the paper choices and a link to the official CIE website with the original specification. Embedded in the file are three word documents that explain the Chemistry, Biology and Physics syllabus in more detail. It is available for less then the price of a cuppa coffee here.

Monday, January 4, 2016

C3. Atomic Structure

This lesson covers an introduction to atomic theory. In includes a Power Point lesson covered the topics outline below. It also includes a revision or homework page (with answer sheet). A ‘Hot Seat Quiz’ that includes the key terms covered in the lesson and a printable of the key figures in Atomic Theory.

The Power Point lesson covers the key terms:
• Atomic theory
• Atoms
• Atomic structure
• Protons
• Neutrons
• Electrons
• Atomic Mass Unit

This is followed by a section covering describing atoms:
• Electron configuration
• Mass Number (Nucleon number)
• Atomic number (proton number)

The last section covers briefly
• Isotopes
• Relative Mass Unit
• Relative Formula Mass

atoms GCSE

This lesson cover the section C3 of the iGCSE unit 0653 combined science (some sections regarding the periodic table will be included in a separate section). It includes:

C3. Atoms, elements and compounds

3.3 Atomic structure and the Periodic Table

1 Describe the structure of an atom in terms of electrons and a nucleus containing protons and neutrons.

2 Describe the build-up of electrons in ‘shells’ and understand the significance of the noble gas electronic structures and of valency electrons (reference to noble gases not included - this will be in periodic table lesson)

3 State the relative charges and approximate relative masses of protons, neutrons and electrons.
4 Define atomic (proton) number and mass (nucleon) number.

5 Use proton number and the simple structure of atoms to explain the basis of the Periodic Table (see section C9), with special reference to the elements with proton numbers 1 to 20. (not yet included in this section)


GCSE science Atoms

Monday, November 2, 2015

C3. Physical and Chemical Changes

 CIE combined Science 0653 C3 Atoms Elements and Compounds.

This lesson covers the following topics
1. Elements
2. Molecules
4. Mixtures.
5. Physical and chemical properties
6. Physical changes and Chemical changes

The lesson includes a Power Point presentation including all the topics outlined above plus a quiz on physical and chemical changes

There is a lab lesson on compounds and mixtures (classic iron fillings and sulphur experiment) with word doc for students and teacher to follow.

The lesson also contains a separate homework exercise (word document)

Covers section first 2 specifications of C3 on the CIE 0653 GCSE Combined Science Course

You can find the lesson here 

GSCE chemistry

igcse101 Chemistry

igcse101 chemistry

Monday, August 31, 2015

Experimental Techniques- Chromotograpgy

 C2. Experimental techniques

1. Describe paper chromatography
2. Interpret simple chromatograms

This is a three part lesson. The first section defines what chromatography is. Next the principle of paper chromatography along with how it works  and the experimental set up and finally the last section covers how to interrupt the chromatograms. 

The lesson includes:
Slides on all of the above

the uses of paper chromatography (exercise)
Homework exercise with some answers (on a separate word document preview below)
As usual for all my lessons I have extra resources at the last page (including videos, notes, exercises and experiments)

Find the lesson here


Monday, August 24, 2015

Science Teaching Resources

Putting it together one link at a time so check back frequently!

1. (Its about time - STEM education) (Howard Hughes Medical Institute - hundreds of free science resources)
3. (education resources from the Royal society of Chemistry)

Thursday, August 20, 2015

C2. Experimental Techniques - Mixtures and Separating Mixtures

The start of C2. This lesson includes a lot of class participation. With slides containing many non labeled diagrams and a hot seat quiz!

The topics covered include:
1. Key terms (solubility, filtrate,distillate etc).
2. Separating mixtures:  Solid and liquid -Filtration
                                   Solids - Evaporation
                                   Liquids - Simple distillation
3. Quiz
4. How to fold filter paper and diagram for how filter paper works
5. Homework page preview here!


Find the complete resource with powerpoint and word homework sheet here:



Wednesday, July 8, 2015

Common Laboratory Equipment

While putting together the lesson on Experimental Techniques I thought it best to include some images of all the apparatus listed on the 0653 Combined Chemistry Syllabus Apparatus List.

By adding other labware, some videos a great flash card resource and a homework page it was been made into a complete lesson. Here is an example question from the homework page:

The lesson can be found here:

Friday, July 3, 2015

The Particulate Nature of Matter

Demonstrate understanding of the terms atom and molecule.

Just finished my lesson on the particulate nature of matter. Difficult to decide what to leave in an what to leave out! 

The finished presentation contains:
  • Definition of matter
  • A slide on the particulate nature of matter
  • Notes explaining how this theory explains the properties of solids, liquids and gases
  • Changes of states (melting evaporating and boiling)
  • Atoms
  • Molecules
  • Questions
  • Resources (video content related to topic, classroom experiments and exercises)

See Lesson Here:

Matter iGCSE 101

Friday, May 22, 2015

Physics Syllabus 0653 Syllabus 2017-2018

Physics Syllabus 0653 Syllabus
The official CIE syllabus can be found here:
It is best to always refer to the original syllabus.

P1. Motion
1 Define speed and calculate average speed from: total distance total time
2 Plot and interpret a speed-time graph and a distance-time graph.
3 Recognise from the shape of a speed-time graph when a body is:
• at rest
• moving with constant speed
• moving with changing speed.
4 Recognise linear motion for which the acceleration is constant, and calculate the acceleration. *
5 Recognise motion for which the acceleration is not constant.*
6 Calculate the area under a speed-time graph to work out the distance travelled for motion with constant acceleration.*
7 Demonstrate a qualitative understanding that acceleration is related to changing speed.

P2. Matter and forces
2.1 Mass and weight
1 Be able to distinguish between the mass and weight of an object.
2 Know that the Earth is the source of a gravitational field.
3 Describe, and use the concept of, weight as the effect of a gravitational field on a mass.

2.2 Density
1 Describe an experiment to determine the density of a liquid and of a regularly shaped solid, and make the necessary calculation using the equation: density = mass / volume or d = m / V
2 Describe the determination of the density of an irregularly shaped solid by the method of displacement, and make the necessary calculation.

2.3 Effects of forces
1 Know that a force is measured in newtons (N).
2 Describe how forces may change the size, shape and motion of a body.
3 Plot and interpret extension-load graphs and describe the associated experimental procedure.
4 State Hooke’s Law and recall and use the expression: force = constant × extension (F = kx).
5 Recognise the significance of the term ‘limit of proportionality’ for an extension / load graph.

P3. Energy, work and power
3.1 Energy
1 Know that energy and work are measured in joules (J), and power in watts (W).
2 Demonstrate understanding that an object may have energy due to its motion (kinetic energy, K.E.) or its position (potential energy, P.E.), and that energy may be transferred and stored.
3 Recall and use the expressions K.E. = 2 1 mv2 and P.E. = mgh *
4 Give and identify examples of energy in different forms, including kinetic, gravitational, chemical, nuclear, thermal (heat), electrical, light and sound.
5 Give and identify examples of the conversion of energy from one form to another, and of its transfer from one place to another.
6 Apply the principle of energy conservation to simple examples.*

3.2 Energy resources
1 Distinguish between renewable and non-renewable sources of energy.
2 Know that the Sun is the source of energy for all our energy resources except geothermal and nuclear.
3 Describe how electricity or other useful forms of energy may be obtained from:
• chemical energy stored in fuel
• water, including the energy stored in waves, in tides, and in water behind hydroelectric dams
• geothermal resources
• heat and light from the Sun (solar cells and panels)
• wind.
4 Give advantages and disadvantages of each method in terms of reliability, scale and environmental impact.
5 Demonstrate a qualitative understanding of efficiency.
6 Recall and use the equation: efficiency = useful energy output energy input × 100%

3.3 Work
1 Relate (without calculation) work done to the magnitude of a force and the distance moved.
2 Describe energy changes in terms of work done.
3 Recall and use W = F × d

3.4 Power
1 Relate (without calculation) power to work done and time taken, using appropriate examples.
2 Recall and use the equation P = E / t in simple systems.

P4. Simple kinetic molecular model of matter
4.1 States of matter
1 State the distinguishing properties of solids, liquids and gases.

4.2 Molecular model
1 Describe qualitatively the molecular structure of solids, liquids and gases.
2 Relate the properties of solids, liquids and gases to the forces and distances between molecules and to the motion of the molecules.
3 Interpret the temperature of a gas in terms of the motion of its molecules.

4.3 Evaporation
1 Describe evaporation in terms of the escape of more energetic molecules from the surface of a liquid.
2 Relate evaporation to the consequent cooling.

P5. Matter and thermal properties
1 Describe qualitatively the thermal expansion of solids, liquids and gases.
2 Identify and explain some of the everyday applications and consequences of thermal expansion.
3 State the meaning of melting point and boiling point.

P6. Transfer of thermal energy
6.1 Conduction
1 Describe experiments to demonstrate the properties of good and bad conductors of heat.
2 Explain heat transfer in solids in terms of molecular motion.

6.2 Convection
1 Recognise convection as the main method of heat transfer in liquids and gases.
2 Relate convection in fluids to density changes.
3 Describe experiments to illustrate convection in liquids and gases.

6.3 Radiation
1 Recognise radiation as the method of heat transfer that does not require a medium to travel through.
2 Identify infra-red radiation as the part of the electromagnetic spectrum often involved in heat transfer by radiation.
3 Describe experiments to show the properties of good and bad emitters and good and bad absorbers of infra-red radiation.

6.4 Consequences of energy transfer
1 Identify and explain some of the everyday applications and consequences of conduction, convection and radiation.

P7. Waves
7.1 General wave properties
1 Describe what is meant by wave motion as illustrated by vibration in ropes and springs and by experiments using water waves.
2 Distinguish between transverse and longitudinal waves and give suitable examples*
3 State the meaning of and use the terms speed, frequency, wavelength and amplitude.
4 Recall and use the equation v = f λ *
5 Identify how a wave can be reflected off a plane barrier and can change direction as its speed changes.*

P8. Light
8.1 Reflection of light
1 Describe the formation and give the characteristics of an optical image formed by a plane mirror.
2 Perform simple constructions, measurements and calculations based on reflections in plane mirrors.
3 Use the law: angle of incidence, i = angle of reflection, r.

8.2 Refraction of light
1 Describe an experimental demonstration of the refraction of light.
2 Identify and describe internal and total internal reflection using ray diagrams.
3 Describe, using ray diagrams, the passage of light through parallel-sided transparent material, indicating the angle of incidence i and angle of refraction r.
4 State the meaning of critical angle.
5 Describe the action of optical fibres, particularly in medicine and communications technology.

8.3 Thin converging lens
1 Describe the action of a thin converging lens on a beam of light, using ray diagrams.
2 Use the terms principal focus and focal length.

 P9. Electromagnetic spectrum
1 Describe the main features of the electromagnetic spectrum.
2 State that all electromagnetic waves travel with the same high speed in vacuum.*
3 Describe the role of electromagnetic waves in:
• radio and television communications (radio waves)
• satellite television and telephones (microwaves)
• electrical appliances, remote controllers for televisions and intruder alarms (infra-red)
• medicine and security (X-rays).
4 Demonstrate an awareness of safety issues regarding the use of microwaves and X-rays.

P10. Sound
1 Describe the production of sound by vibrating sources.
2 Describe transmission of sound in air in terms of compressions and rarefactions.*
3 State the approximate human range of audible frequencies.
4 Demonstrate understanding that a medium is needed to transmit sound waves.
5 Describe an experiment to determine the speed of sound in air.
6 State the order of magnitude of the speed of sound in air, liquids and solids.*
7 Relate the loudness and pitch of sound waves to amplitude and frequency.
8 Describe how the reflection of sound may produce an echo.

P11. Electricity
11.1 Electrical quantities
1 Demonstrate understanding of current, potential difference and resistance, and use with their appropriate units.
2 Use and describe the use of an ammeter and a voltmeter.

11.2 Electric charge
1 Describe simple experiments to show the production and detection of electrostatic charges.
2 State that there are positive and negative charges.
3 State that unlike charges attract and that like charges repel.
5 Distinguish between electrical conductors and insulators and give typical examples.
4 Describe an electric field as a region in which an electric charge experiences a force.*

11.3 Current and potential difference
1 State that current is related to the flow of charge.
2 State that the current in metals is due to a flow of electrons.
3 Use the term potential difference (p.d.) to describe what drives the current between two points in a circuit.

11.4 Resistance
1 State that resistance = p.d. / current and understand qualitatively how changes in p.d. or resistance affect current.
2 Recall and use the equation R = V / I.
3 Relate (without calculation) the resistance of a wire to its length and to its diameter.*
4 Describe an experiment to determine resistance using a voltmeter and an ammeter.

11.5 Electrical energy
1 Recall and use the equations P = IV and E = IVt

11.6 Dangers of electricity
1 Identify electrical hazards including:
• damaged insulation
• overheating of cables
• damp conditions.
2 Demonstrate understanding of the use of fuses.

P12. Electric circuits
12.1 Circuit diagrams
1 Draw and interpret circuit diagrams containing sources, switches, resistors (fixed and variable), lamps, ammeters, voltmeters and fuses.

12.2 Series and parallel circuits
1 Demonstrate understanding that the current at every point in a series circuit is the same.
2 Recall and use the fact that the sum of the p.d.s across the components in a series circuit is equal to the total p.d. across the supply.*
3 Calculate the combined resistance of two or more resistors in series.
4 State that, for a parallel circuit, the current from the source is larger than the current in each branch.
5 Recall and use the fact that the current from the source is the sum of the currents in the separate branches of a parallel circuit.*
6 State that the combined resistance of two resistors in parallel is less than that of either resistor by itself.
7 State the advantages of connecting lamps in parallel in a lighting circuit.

Biology Syllabus 0653 Syllabus 2017-2018

Biology Syllabus 0653 Syllabus
The official CIE syllabus can be found here:
It is best to always refer to the original syllabus.

B1. Characteristics of living organisms
1 List and describe the characteristics of living organisms.

B2. Cells
2.1 Cell structure and organisation
1 State that living organisms are made of cells.
2 Identify and describe the structure of a plant cell (palisade cell) and an animal cell (liver cell), as seen under a light microscope.
3 Relate the structures seen under the light microscope in the plant cell and in the animal cell to their functions.*
4 Describe the differences in structure between typical animal and plant cells.
5 Calculate magnification and size of biological specimens using millimetres as units.

2.2 Movement in and out of cells
1 Define diffusion as the net movement of molecules from a region of their higher concentration to a region of their lower concentration down a concentration gradient, as a result of their random movement.
2 Describe the importance of diffusion of gases and solutes and of water as a solvent.

B3. Enzymes
1 Define enzymes as proteins that function as biological catalysts.
2 Investigate and describe the effect of changes in temperature and pH on enzyme activity.
3 Explain the effect of changes in temperature and pH on enzyme activity.

B4. Nutrition
4.1 Nutrients
1 List the chemical elements that make up:
2 Describe the structure of large molecules made from smaller basic units, i.e.
•simple sugars to starch and glycogen
•amino acids to proteins
•fatty acids and glycerol to fats and oils.
3 Describe tests for:
• starch (iodine solution)
• reducing sugars (Benedict’s solution)
• protein (biuret test)
• fats (ethanol)
4 List the principal sources of, and describe the importance of:
• carbohydrates
• fats
• proteins
• vitamins (C and D only)
• mineral salts (calcium and iron only)
• fibre (roughage)
• water.
5 Describe the deficiency symptoms for:
• vitamins (C and D only)
• mineral salts (calcium and iron only)
6 Describe the use of microorganisms in the manufacture of yoghurt.

4.2 Plant nutrition
1 Define photosynthesis as the fundamental process by which plants manufacture carbohydrates from raw materials using energy from light.
2 Explain that chlorophyll traps light energy and converts it into chemical energy for the formation of carbohydrates and their subsequent storage. *
3 State the word equation for the production of simple sugars and oxygen.
4 State the balanced equation for photosynthesis in symbols 6CO2 + 6H2O light chlorophyll C6H12O6 + 6O2*
5 Investigate the necessity for chlorophyll, light and carbon dioxide for photosynthesis, using appropriate controls.
6 Investigate and state the effect of varying light intensity on the rate of photosynthesis (e.g. in submerged aquatic plants).*
7 Describe the intake of carbon dioxide and water by plants.
8 Identify and label the cuticle, cellular and tissue structure of a dicotyledonous leaf, as seen in cross-section under the light microscope.

4.3 Animal nutrition
1 State what is meant by the term balanced diet and describe a balanced diet related to age, sex and activity of an individual.
2 Describe the effects of malnutrition in relation to starvation, coronary heart disease, constipation and obesity.*
3 Identify the main regions of the alimentary canal and associated organs, including mouth, salivary glands, oesophagus, stomach, small intestine: duodenum and ileum, pancreas, liver, gall bladder, large intestine: colon and rectum, anus.
4 Describe the functions of the regions of the alimentary canal listed above, in relation to ingestion, digestion, absorption, assimilation and egestion of food.
5 Define digestion as the breakdown of large, insoluble food molecules into small, water-soluble molecules using mechanical and chemical processes.
6 Identify the types of human teeth and describe their structure and functions.
7 State the causes of dental decay and describe the proper care of teeth.
8 State the significance of chemical digestion in the alimentary canal in producing small, soluble molecules that can be absorbed.
9 Define absorption as movement of digested food molecules through the wall of the intestine into the blood.
10 Identify the small intestine as the region for the absorption of digested food.

B5. Transportation
5.1 Transport in plants
1 State the functions of xylem and phloem.
2 Identify the positions of xylem tissues as seen in transverse sections of unthickened, herbaceous, dicotyledonous roots, stems and leaves.
3 Identify root hair cells, as seen under the light microscope, and state their functions.
4 Relate the structure and functions of root hairs to their surface area and to water and ion uptake.*
5 Investigate, using a suitable stain, the pathway of water through the above-ground parts of a plant.
6 Define transpiration as evaporation of water at the surfaces of the mesophyll cells followed by loss of water vapour from plant leaves, through the stomata.
7 Describe the effects of variation of temperature, humidity and light intensity on transpiration rate.

5.2 Transport in humans
1 Describe the circulatory system as a system of tubes with a pump and valves to ensure one-way flow of blood.
2 Describe the double circulation in terms of a low-pressure circulation to the lungs and a high-pressure circulation to the body tissues, and relate these differences to the different functions of the two circuits.*
3 Describe the structure of the heart, including the muscular wall and septum, atria, ventricles, valves and associated blood vessels.
4 Describe coronary heart disease in terms of the blockage of coronary arteries and state the possible causes (diet, stress and smoking) and preventive measures. *
5 Describe the function of the heart in terms of muscular contraction and the working of the valves.
6 Investigate the effect of physical activity on pulse rate.
7 Investigate, state and explain the effect of physical activity on pulse rate.*
8 Identify red and white blood cells as seen under the light microscope on prepared slides, and in diagrams and photomicrographs.
9 Describe the structure and functions of arteries, veins and capillaries.
10 Explain how structure and function are related in arteries, veins and capillaries.*
11 List the components of blood as red blood cells, white blood cells, platelets and plasma.
12 State the functions of blood:
• red blood cells – haemoglobin and oxygen transport
• white blood cells – phagocytosis and antibody formation
• platelets – causing clotting (no details)
• plasma – transport of blood cells, ions, soluble nutrients, hormones and carbon dioxide.

B6. Respiration
6.1 Respiration and energy
1 Define respiration as the chemical reactions that break down nutrient molecules in living cells to release energy.
2 State the uses of energy in the body of humans: muscle contraction, protein synthesis, cell division, growth, the passage of nerve impulses and the maintenance of a constant body temperature.
3 State the word equation for aerobic respiration.
4 Define aerobic respiration as the release of a relatively large amount of energy in cells by the breakdown of food substances in the presence of oxygen.
5 State the equation for aerobic respiration using symbols (C6H12O6 + 6O2 → 6CO2 + 6H2O).

6.2 Gas exchange
1 Identify on diagrams and name the larynx, trachea, bronchi, bronchioles, alveoli and associated capillaries.
2 List the features of gas exchange surfaces in animals. *
3 Explain the role of mucus and cilia in protecting the gas exchange system from pathogens and particles.*
4 Describe the effects of tobacco smoke and its major toxic components (tar, nicotine, carbon monoxide, smoke particles) on the gas exchange system.*
5 State the differences in composition between inspired and expired air.

6 Use limewater as a test for carbon dioxide to investigate the differences in composition between inspired and expired air.
7 Investigate and describe the effects of physical activity on rate and depth of breathing.
8 Explain the effects of physical activity on rate and depth of breathing.*

B7. Co-ordination and response
7.1 Hormones
1 Define a hormone as a chemical substance, produced by a gland, carried by the blood, which alters the activity of one or more specific target organs and is then destroyed by the liver.
2 State the role of the hormone adrenaline in chemical control of metabolic activity, including increasing the blood glucose concentration and pulse rate.
3 Give examples of situations in which adrenaline secretion increases.

7.2 Tropic responses
1 Define and investigate geotropism (as a response in which a plant grows towards or away from gravity) and phototropism (as a response in which a plant grows towards or away from the direction from which light is coming).
2 Explain the chemical control of plant growth by auxins including geotropism and phototropism in terms of auxins regulating differential growth.

B8. Reproduction
8.1 asexual and sexual reproduction
1 Define asexual reproduction as the process resulting in the production of genetically identical offspring from one parent.
2 Define sexual reproduction as the process involving the fusion of haploid nuclei to form a diploid zygote and the production of genetically dissimilar offspring.

8.2 Sexual reproduction in plants
1 Identify and draw, using a hand lens if necessary, the sepals, petals, stamens, anthers, carpels, ovaries and stigmas of one locally available, named, insect-pollinated, dicotyledonous flower, and examine the pollen grains under a light microscope or in photomicrographs.
2 Use a hand lens to identify and describe the anthers and stigmas of one locally available, named, wind-pollinated flower.*
3 State the functions of the sepals, petals, anthers, stigmas and ovaries.
4 Candidates should expect to apply their understanding of the flowers they have studied to unfamiliar flowers.
5 Define pollination as the transfer of pollen grains from the male part of the plant (anther or stamen) to the female part of the plant (stigma).
6 Name the agents of pollination.
7 Compare the different structural adaptations of insect-pollinated and wind-pollinated flowers.*
8 Investigate and state the environmental conditions that affect germination of seeds: requirement for water and oxygen, suitable temperature.

8.3 Sexual reproduction in humans
1 Identify on diagrams of the male reproductive system: the testes, scrotum, sperm ducts, prostate gland, urethra and penis, and state the functions of these parts.
2 Compare male and female gametes in terms of size, numbers and mobility.*
3 Identify on diagrams of the female reproductive system: the ovaries, oviducts, uterus, cervix and vagina, and state the functions of these parts.
4 Describe the menstrual cycle in terms of changes in the uterus and ovaries.
5 Describe fertilisation in terms of the joining of the nuclei of male gamete (sperm) and the female gamete (egg).
6 Outline early development of the zygote simply in terms of the formation of a ball of cells that becomes implanted in the wall of the uterus.
7 Indicate the functions of the amniotic sac and amniotic fluid. *
8 Describe the function of the placenta and umbilical cord in relation to exchange of dissolved nutrients, gases and excretory products (no structural details are required)*
9 Describe the advantages and disadvantages of breast-feeding compared with bottle-feeding using formula milk. *
10 Describe the methods of transmission of human immunodeficiency virus (HIV), and the ways in which HIV / AIDS can be prevented from spreading.
11 Outline how HIV affects the immune system in a person with HIV / AIDS.*

B9 Energy flow in ecosystems
1 State that the Sun is the principal source of energy input to biological systems.
2 Define the terms:
•food chain as showing the flow of energy (food) from one organism to the next, beginning with a producer (e.g. mahogany tree → caterpillar → song bird → hawk)
•food web as a network of interconnected food chains showing the energy flow through part of an ecosystem
•producer as an organism that makes its own organic nutrients, usually using energy from sunlight, through photosynthesis
• consumer as an organism that gets its energy by feeding on other organisms
• herbivore as an animal that gets its energy by eating plants
• carnivore as an animal that gets its energy by eating other animals.
3 Describe energy losses between trophic levels.*
4 Define the terms:
•decomposer as an organism that gets its energy from dead or waste organic matter •ecosystem as a unit containing all of the organisms and their environment, interacting together, in a given area, e.g. decomposing log or a lake
•trophic level as the position of an organism in a food chain or food web. *
5 Explain why food chains usually have fewer than five trophic levels. *
6 Describe the carbon cycle.
7 Discuss the effects of the combustion of fossil fuels and the cutting down of forests on the oxygen and carbon dioxide concentrations in the atmosphere.*

B 10. Human influences on the ecosystem

1 List the undesirable effects of deforestation (to include extinction, loss of soil, flooding, carbon dioxide build-up).

2 Describe the undesirable effects of pollution to include:

• water pollution by sewage and chemical waste

• air pollution by greenhouse gases (carbon dioxide and methane) contributing to global warming.

3 Describe the undesirable effects of overuse of fertilisers (to include eutrophication of lakes and rivers).*

4 Discuss the causes and effects on the environment of acid rain, and the measures that might be taken to reduce its incidence. *

5 Explain how increases in greenhouse gases (carbon dioxide and methane) are thought to cause global warming.*

6 Describe the need for conservation of:

•species and their habitats

•natural resources (limited to water and non-renewable materials including fossil fuels).