The Circulatory System: Heart
Transporting materials between cells is necessary for multicellular organisms. Like many animals, the heart plays a key role in the human circulatory system, which transports blood around the body.
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GCSE Science learning topics and material for students in Year 7 to Year 11.
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The Lungs
Your cells require oxygen for respiration, so you need to get it from the air into your bloodstream. You must also expel carbon dioxide from your bloodstream. All of this occurs in your lungs. Your lungs are forced to take in and expel air when you breathe.
Cell Organisation Revision Notes and Practice Quiz
There are trillions of cells in multicellular organisms like humans. Those cells have to work together to keep the organism going, which requires organisation.
Exchanging Substances Revision Notes and Practice Quiz
You need to know about a few examples of exchange surfaces. Mammals exchange gases in their lungs and absorb nutrients in their small intestines. In plants, gas exchange occurs in the leaves. In fish, gas exchange occurs in the gills.
Exchange Surfaces Revision Notes and Practice Quiz
Substances dissolved in water are called soluble. In order to survive, living organisms must be able to exchange dissolved substances with their environment. Surface area and size affect the pace at which this can occur.
Culturing Microorganisms Revision Notes and Practice Quiz
The most common way microorganisms are grown (cultured) is in a "culture medium", a combination of carbohydrates, minerals, proteins and vitamins. A nutrient broth solution or solid agar jelly can be used as the culture medium.