Science Projects Index

Skin Colour and Sunlight

Wrap a piece of medical plaster around one of your finger and keep it there for three days. At the end of that period, open the plaster and observe the skin. You will find the skin, which was covered, to be pale. There is discolouration. This is because that part did not get exposed to sunlight for the last three days, while the rest of the areas did get sunlight. Sunlight enhances the production of melanin a substance which gives the dark colour to our skin.

Movement of Our Joints

Let's see how our joints work. Take a wooden block and slide it on a wooden board.

Now cover the board and the underside of the block with aluminium foil and notice the easiness of movement. Pour some oil on the board and spread it. Now move the block.

The movement is very smooth. It's the same way the fluid present in our bone joints make the movements easier.