Odd One Out

Seeds of life

Activity overview

15 mins
Ages 5 – 7

Science topics:


Put your class' observation skills to the test with these three different seeds. This activity is great for promoting observation and discussion skills.

Run the activity

1. Show the three images above and ask everyone to come up with as many similarities and differences as they can. If they get stuck, prompt them to think about:

  • appearance
  • what they do
  • where they might be found

2. Then, everyone needs to decide which one is the odd one out and why. Encourage a reason for every answer and there is no wrong answer!

Background science

The three images are showing sunflower seeds, horse chestnuts and broad beans. If humans ever wanted to live on Mars, they would need to grow their own food using artificial heat and light. The easiest way to transport plants to Mars would be in their dormant state as seeds. They are a lot more robust in this state and do not need light or water. They are also a lot lighter at this stage in their life cycle.  Many seeds will remain viable for several years, which would make them ideal for a long journey to Mars.


The ExoMars mission is looking for signs of life on Mars. We've got lots of activities to support your own Mars exploration. Read more on our blog! 

Take it further

Gather as many seeds as possible and give children the opportunity to explore them. They might like to try planting all of these seeds and see what happens over the coming weeks. They could also discuss which seeds would be best to take to Mars. For example, the avocado might not be very useful, as it grows into a very large plant before it grows any fruit. Likewise, the conker grows into a plant that is very big and takes a long time to fruit, but also the conkers are not suitable for humans to eat! Watch some different vegetables as they're harvested - would any of these be suitable on Mars? Encourage the children to think about if you need large seeds to grow large plants

Suitable crops could include lettuce, which grows and sets seed quickly and beans, which do not grow quite as quickly but would provide a good source of protein. Children may also enjoy the problem solver activity Get growing on Mars.