Unit 7 Living Things and Air
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7.1 Air
Major components of air Recognise that air is a mixture of gases
State the percentage of main gases in air
Properties of oxygen, carbon dioxide and nitrogen
State the main properties of oxygen, carbon dioxide and nitrogen
Describe the tests for oxygen, carbon dioxide and water
Give examples of the daily applications of oxygen, carbon dioxide and nitrogen
Read the story about the discovery of oxygen
Perform practical works to test for oxygen, carbon dioxide and water
Search information on the daily
applications of oxygen, carbon dioxide and nitrogen
7.2 Photosynthesis Recognise that photosynthesis is the process that plants make their own food
State that light energy is converted to chemical energy in food during photosynthesis in plants
Write the word equation of photosynthesis
Write the chemical equation of photosynthesis
Perform practical work to test for starch in green leaves
Perform practical work to show that oxygen is produced during photosynthesis
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Understand that light, chlorophyll, carbon dioxide and water are the necessary factors for photosynthesis
Recognise that the carbohydrates
(glucose) produced in plants can be used immediately or stored as starch for later use
Recognise the significance of
photosynthesis of plants to other living things
Plan and conduct investigations to find out the necessary factors for
photosynthesis
Recognise that plants are the producers and animals are the consumers in most food chains
Construct food chains to show the feeding relationship between different living things
7.3 Respiration State that food (e.g. carbohydrates) is the source of energy for all living things
Recognise that the chemical energy stored in food can be changed by our body into other useful forms of energy to support body activities
Describe respiration as a process in which food is broken down in cells to release
Perform practical work to heat a small amount of water by burning food
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energy in usable form for cells
Write the word equation of respiration
Write the chemical equation of respiration
7.4 Gas exchange in plants and animals
Gas exchange in plants Understand that the net gas exchange in plants depends on the relative rate of photosynthesis and respiration taken place
Recognise that gas exchange in plants is carried out through the stomata
Perform practical work to find out the change in carbon dioxide content in a boiling tube with a leave under light and dark conditions respectively
Examine a prepared slide of leaf
epidermis to observe the stomata under a microscope
Gas exchange in animals Compare the temperature and the composition of gases (oxygen, carbon dioxide and water vapour) between inhaled and exhaled air
Perform practical work to compare oxygen, carbon dioxide and water vapour content of inhaled and exhaled air
Perform practical work to find out the change in carbon dioxide content in a boiling tube with an animal (e.g.
mealworm, grasshopper)
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Students should learn Students should be able to Suggested learning and teaching activities
Identify the main parts of the breathing system in humans
State that gas exchange in humans takes place at the air sacs
State the significance of gas exchange to body cells
Describe the exchange of gases between air sacs and the surrounding blood capillaries
Describe how smoking affects gas exchange in humans
Recognise that smoking is harmful to health (e.g. causing lung cancer and heart diseases)
Examine a human torso to identify the main parts of the breathing system
Dissect pig lungs to observe the structure of the lungs
View animation about the gas exchange process at air sacs
Perform a demonstration to show how smoking affects a pair of pig’s lungs
Search information on the long term effects of smoking on health
Design a poster or make a video clip to persuade smokers to quit smoking
Search information about electronic cigarette and its health effect, and discuss whether its sale should be regulated by the government
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Students should learn Students should be able to Suggested learning and teaching activities
7.5 Balance of carbon dioxide and oxygen in Nature
Understand that there is a natural balance of carbon dioxide and oxygen in the atmosphere
Recognise some human activities are disrupting the balance of carbon dioxide in Nature
State carbon dioxide as one of the greenhouse gases
Describe the effects of the increasing amount of carbon dioxide in the atmosphere on the environment
Watch a video clip about the relationship between the trend of carbon dioxide content in the atmosphere and global warming, and the climate change that result
Design a poster or make a video clip to promote low carbon living
Visit the Zero Carbon Building
7.6 Air quality Be aware of the effect of air quality on our health
Give examples of common air pollutants
Recognise the health advice related to the Air Quality Health Index (AQHI)
Search information on some diseases related to poor air quality
Conduct a project to investigate the AQHI of the district where your school is
located for a particular period of time and give appropriate health advice to students in your school
Unit 8 Making Use of Electricity