Why are eyes different colours and why do dolphins jump? Try our kids’ quiz

Molly Oldfield
·2-min read
<span>Illustration: Hennie Haworth/The Guardian</span>
Illustration: Hennie Haworth/The Guardian

  1. Ivy, 8, asks: why are eyes different colours?

    1. Your eyes change colour depending on how sunny it is where you live

    2. Your eyes change colour depending on the food you eat

    3. Your eye colour is created by a pigment made by your body called melanin

    4. Eyes are different colours so you can tell people apart

  2. Jacob, 7, asks: how many drops of water are there in the sea?

    1. A billion drops

    2. Infinity drops

    3. About a googolplex drops

    4. Very roughly 26 quadrillion drops

  3. Arlo, 7, asks: do starfish have eyes?

    1. Yes, they have star-shaped eyes in the middle of the star

    2. No – starfish have no eyes

    3. Yes, they have eyes on the ends of their arms

    4. Starfish have two eyes just like we do

  4. Maia, 6, asks: how much of the ocean is coral reef?

    1. Over half of the ocean is coral reef

    2. The whole seabed used to have coral reef but now it’s all disappeared

    3. 25% of the ocean is coral reef

    4. Less than 0.1% of the ocean’s floor is coral reef

  5. Zahra, 4, asks: why do dolphins jump?

    1. To catch flying fish

    2. For fun and to communicate with other dolphins

    3. To escape sharks underneath them

    4. To get some warm sunshine on their skin

Solutions

1:C - The coloured part of your eye is the iris, and the colour depends on how much of a pigment called melanin your body makes – melanin also creates skin and hair colour., 2:D - There are about 1.33 billion cubic kilometres of water in the world’s oceans: 1 cubic kilometre is equal to 1 trillion litres, and 1 litre contains roughly 20,000 drops of water. This would mean 26 quadrillion drops of water in the sea – or 26 followed by 24 zeros (in the US this would be called 26 septillion). It’s just a rough estimate! But we do know the sea contains a HUGE number of drops of water. , 3:C - Starfish have eyes on the ends of their arms. They can’t see a lot – a 2018 study found that the image formed by a blue sea star’s eye has about 200 pixels, enough to find big things like the reef where they live and eat food., 4:D - Less than 0.1% of the seabed is coral reef but it’s full of life, with 25% of species found in all of the oceans living on coral reef., 5:B - Dolphins jump because they find it fun! They also get a good view from up there and can communicate with other dolphins.

Scores

  1. 5 and above.

  2. 4 and above.

  3. 3 and above.

  4. 2 and above.

  5. 0 and above.

  6. 1 and above.

Molly Oldfield hosts Everything Under the Sun, a weekly podcast answering children’s questions, out now as a book.

Does your child have a question? Submit one here

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