What it shows
Washing-up liquid breaks open the cell membranes, salt helps the DNA clump together, and ice-cold alcohol makes the DNA come out of solution as white strands you can see.
This idea has a short entry only. For the science behind it, read the sentence above with your textbook and ask your teacher to explain the law or idea it shows, so you can describe it in your own words.
Materials
- A ripe banana or strawberries
- Washing-up liquid, salt and water
- A strainer and a tall glass
- Ice-cold rubbing alcohol (isopropyl)
- A wooden skewer
Safety
For this project: Rubbing alcohol is flammable and poisonous: an adult should pour it, keep it away from flames, and nobody should drink it.
Never use mains electricity: power models with cells, batteries or a low-voltage adapter. Sharp and hot tools, flames and lab chemicals need an adult or your teacher beside you. Keep magnets, button cells and small parts away from young children, and wash your hands after making.
How to go about it
Numbered steps have not been written for this idea yet. Plan it with your teacher: sketch the design with measurements, build one part at a time, test each part, and write every observation with the date. The free ebooks below have step-by-step projects of the same kind.
Free ebooks for this project
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Make the heart, lungs, kidney, eye, cell and more, and explain them well
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Free, well-known places to explore the subject further. Ask a grown-up before you sign up for anything or type your name anywhere.