Super seed spinner
Make this simple seed spinner to show how seeds are dispersed.
Quick facts
Learning objectives:
To learn how seeds need to be dispersed to optimise their chance of survival
1
To learn about how the structure of fruits and seeds relate to how their seeds are dispersed
2
To understand that seeds can be dispersed by a variety of methods including wind and animals
3
Science: Study seed dispersal methods and their relevance for plant survival
4
Geography: Understand environmental factors that influence seed dispersal
5
Maths: Measure seed travel distance and time using variables like size and weight
6
Introduction
- Give each pupil a seed large enough to write their initials on (e.g. a conker or acorn). Take the pupils outside and ask them to hide their seeds
- Ask them: What animals hide seeds and why? What happens to these seeds?
- Seeds have evolved over time to be dispersed (moved). An oak tree produces 50,000 acorns a year but only two or three will grow into mature oak trees. By moving away from the parent plant, a seed will increase the probability of survival. How does this increase seed survival?
Key vocabulary
Seed | Dispersal | Lifecycle | Wings | Float | Encased | Hooks | Fruit
Essential information
- Seeds are formed when pollen from the male part of the flower, lands on the female part of the flower. takes place and the ovule develops into a seed
- A fruit is a seed-bearing structure that develops from the ovary of a flower
Resources
- Large seeds (conkers and acorns)
- Sycamore seeds - dandelion seed heads
- Seeds with hooks - cleaver or geum
- Seeds with attractive fruits (cherries or raspberries)
- A selection of seeds for the ‘most likely to..’ activity
- Materials for ‘Make a seed spinner’ activity
Activities
How are the seeds dispersed?
- Get your pupils to either throw a sycamore seed in the air or to gently blow a dandelion seed head. Observe closely and describe what happens to the seeds
- Imagine how much further the seeds would travel on a windy day. What are the features of seeds dispersed by wind?
- Ask for another volunteer to be an animal and attach some seeds with hooks (such as burdock seeds), to their clothing. You could use ping pong balls with velcro dots attached, to demonstrate the same effect. Ask them to jump up and down, the seed will remain firmly stuck until the ‘animal’ scratches itself
- Some seeds are encased in a fruit that is tempting for animals (and birds) to eat. Is this the end for the seed? Think about what will happen next to all the dispersed seeds
Most likely to?
- In groups, explore and decide from a selection of seeds, which is their most likely method of seed dispersal. Base this on categories such as size, weight, shape, hardness and colour
- Use these characteristics to sort the seeds. Are there any common findings for seeds dispersed by wind or animals?
- Use the resource make a seed spinner . Can you improve the design to make your seed travel a longer distance? Can you add features you have discovered in your investigations into seed dispersal and produce the perfect seed?
Decide how you could record your findings:
- What will you measure? Think about distance the seed can travel or time taken to reach the ground
- What are the variables that you could change? Think about the weight and size of the seed
Plenary
- Go back outside to find the seeds hidden at the beginning of the session. It is surprisingly difficult to find them all
- Ask pupils to think of an advantage and disadvantage of seed dispersal by animal
- In their opinion, who would win the fight for survival - wind or animal-dispersed seeds?
Research: How else can a plant disperse its seeds? Find examples to share with each other.
