One of the Required Practicals you need to revise for Chemistry is all about chromatography. Chroma actually means purity or intensity of colour, but how much do you actually know about colour?
Scientists estimate that the human eye can distinguish between up to 10 million colours. However, women see more shades of red than men. This is because the gene to see red sits on the X chromosome. Therefore, women have two copies of it and men just one.
Humans do see more colours than many animals. There are however some animals which see colours we cannot. Spiders can see ultraviolet light, whereas snakes can see infrared light! Some snakes, such as pythons and boas have holes on their faces called pit organs. These contain a membrane which detects infrared radiation from up to 1 metre away. This means, at night, snakes are able to see an image of their prey, or predator! They have their own in-built infra-red camera.
Bees and butterflies can also see in ultraviolet. Special ultraviolet patterns on the leaves and petals of plants act like “landing strips”, guiding the insects into the flower. If you want to attract more bees to your garden, research shows their favourite colours are purple, violet and blue!
If you are revising for the Required Practicals for AQA Combined Science Paper 2 this year – try our guide. You will find a brief description of what you need to know about each practical. As always questions and answers are included.
Click below to see the guide.