Your eyes alone contain over 100 million light-detecting cells. Explore how the eye and ear convert the world around you into nerve signals.
Light enters the eye and is focused by the lens onto the retina, which contains rod cells (for dim light, black-and-white vision) and cone cells (for colour vision in bright light).
What is the difference between rod cells and cone cells in the retina?
Rod cells detect dim light in black and white; cone cells detect colour but need brighter light to work well
Sound waves travel through the outer and middle ear before reaching the cochlea in the inner ear, where they are converted into nerve impulses sent to the brain.
Which structure in the ear converts sound vibrations into nerve impulses?
The cochlea
1. Which part of the eye focuses light onto the retina?
2. Which retinal cells detect dim light in black and white?
3. Which retinal cells detect colour?
4. Why can't you see colours well in very dim light?
5. Which structure in the inner ear converts sound vibrations into nerve impulses?
6. Name the five basic tastes detected by taste buds on the tongue.
7. What sense organ contains taste buds?
8. Why do many animals active mainly at night have eyes with more rod cells than cone cells?
9. Which sense organ detects smell?
10. Why might someone with a blocked nose find it harder to taste food properly?