The 6 mark question Please use the proforma provided until students are aware of what to do.

Evidence over the past thirty years has made Scientists concerned about the damage that we are doing to the Earths atmosphere. The graph below shows how skin cancer rates have changed over the past 30 yrs. Use the graph to describe the trend in skin cancer rates. Outline the causes of skin cancer and explain how human activity is thought to be linked to the above Describe the action taken by governments to limit this damage.

MarksAnswerDetail 1-2 Basic description how skin cancer rates have changed. Answer related to the Ozone layer and UV radiation (CFC’s mentioned) Discussion of “reducing pollution”  Skin cancer rates have gone up over the last 30 yrs  Human activity has damaged the ozone layer because of the release of CFC’s  this damage is letting through more UV light 3-4 Basic description how skin cancer rates have changed but with added detail. Answer links the Ozone layer and UV radiation (CFC emission related to thinning/depletion) to the reasons for cancer developing Government response outlined  Added detail may include “skin cancer rates have more than doubled”  Basic discussion of how UV Radiation causes skin cancer: mention of DNA being damaged or altered by high frequency UV,  CFC emission causes depletion/thinning/hole to develop in the ozone layer  Government responded by reducing (or banning in EU) CFC emissions 5-6Detailed analysis of the graph Detailed explanation the structure of the atmosphere (ozone layer) and the absorption of UV radiation Detailed explanation of the damage caused by CFC’s and how this is linked to the graph Detailed description of the worlds response Answer should the responses for 4 marks and could include (for full 6): Graph  Rates have more than doubled for women, trebled for men  Reasons for fluctuations (bad weather, less sun)  Understanding of unit used (per 100,000) Ozone  thin layer high up (stratosphere) which absorbs high frequency (short wavelength UV)  CFC molecules destroy ozone molecules resulting in thinning of layer and increased UV levels reaching ground Reasons  Understanding that cancer is cells dividing/copying themselves uncontrollably  UV absorbed by skin and radiation causes mutations by damaging DNA (random process) Response  Possible mention of Montreal Protocol  Worldwide agreement SPAG correct and good use of technical terms

Why might a house at the bottom of a hill be able to receive a good radio signal but get very poor TV reception?

The Mark Scheme 1.The transmitters are not in direct line of sight of the house as the house is in a valley (1) 2.The TV signal has a higher frequency/shorter wavelength than the radio (1 max) (or opposite argument for radio waves 3.The house receives the radio signal because of diffraction (1) 4.Diffraction happens best when the gap or object in the way is similar in size to the wavelength (1) 5.The wavelength of the radio waves are similar in size to the hill (so they diffract well) (1) 6.The wavelength of the TV waves are much smaller than the hill (so they do NOT diffract well) (1)

Some people worry that using mobile phones may harm users, and have health risks. Studies over many years have not shown clear evidence that using mobile phones causes harm. Explain why some people are worried about the use of mobile phones by young people. Suggest some ways to reduce the possible risk of harm.

For 6 marks – you must have: most of these points AND a clear structure that is easy to read AND excellent spelling, grammar, paragraphing and punctuation For 3 marks – you must have: 2 or 3 of these points AND clear sentences which make sense AND mainly good spelling, grammar, paragraphing, and punctuation Suggest why people worry e.g. cells may absorb microwaves, warming up and changing cells Say why young people are vulnerable e.g. may use phones for many years State and explain several ways to reduce harm e.g. use phone less often to reduce exposure; use phones fitted with microwave screening to reduce the level of exposure

Microwaves and infra red waves are both types of waves. Microwaves and infra-red waves are both used for communication and cooking. Describe how they are both used for communication and cooking. Describe how these waves are similar and how they are different. Your written communication will also be assessed.

Describe how microwaves can be used for cooking. (need to include idea that the wave energy is absorbed by water/fat/sugar).[1mark] Describe how microwaves can be used for communication. Need to include some detail e.g. Used by mobile phones Received and transmitted by mobile phone masts Can be sent into space to be retransmitted to Earth by satellites.[1mark] Describe how IR waves are used for cooking. Need to include some detail e.g. Emitted by hot objects Heat up objects that absorb them Used in grilling/toasting Absorbed better by dark surfaces [1mark] Describe how IR waves are used in communication. Could refer to Use in optical fibres Use in remote controls[1mark] Describe one similarity and one difference (both needed for mark). Possible answers: Both are electromagnetic waves Both are transverse waves Both travel at the speed of light Microwaves have a lower frequency Microwaves have a longer wavelength Produced and absorbed in different ways[1mark] SPAG mark – answer is well structured and uses correct spelling, punctuation and grammar. [1mark]

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