Does the following question on ‘Seed Dispersal’ look familiar to you?
Source: Maris Stella High School (Primary) – 2012 P6 Science Preliminary Examination Paper [Q31]
Many primary school students are able to identify the method of seed dispersal easily in most questions.
Does your child know how to explain the location of the seedlings with respect to the parent plant?
It is a common sight to see students struggling to structure their thought processes using the necessary keywords.
Based on my experience, many students tend to associate questions on Seed Dispersal with answers involving the key characteristics of the fruit/seed. Hence, they get confused when a question on Seed Dispersal is slightly different from the norm.
As such, in today’s article, I’ll be uncovering the four seed dispersal methods that your child should know. In addition, your child will be learning how to use our answering techniques to tackle questions like the one posted above.
Let us take a look at the key characteristics of the fruit/seed for the 4 types of dispersal methods, which were first introduced in the previous post ‘Pollination VS Seed Dispersal – What’s The Difference?!’.
In order to answer questions on Seed Dispersal correctly, your child needs to know how to link the characteristics of the fruit/seed with the respective seed dispersal method.
Method 1: Wind
As fruits/seeds dispersed by wind are light and have wing-like structures or feather-like structures, they have a larger exposed surface area in contact with the air.
These structures increase the amount of air resistance acting on the fruits/seeds, allowing them to stay in the air for a longer period of time and would thus follow the direction of the wind during dispersal.
Therefore, fruits/seeds dispersed by wind would be found far away from the parent plant in the direction of the wind. (IMPORTANT!: Link-back Sentence!)
Method 2: Water
Fruits/seeds dispersed by water have waterproof coverings and fibrous husks, which trap air, allowing them to float on water.
Therefore, fruits/seeds dispersed by water would be found near water bodies. (IMPORTANT!: Link-back Sentence!)
Method 3: Animal
Fruits/seeds dispersed by animals have either one of the following characteristics:
- Indigestible seeds (usually with juicy flesh surrounding it) that are either:
- Hook-like structure
Type 1: Fruit with small and indigestible seeds
Some animals eat fruits containing small and indigestible seeds.
As a result, these seeds will be passed out together as waste materials far away from the parent plant.
Type 2: Fruit with large and indigestible seeds
On the other hand, some animals eat fruits with large and indigestible seeds.
As a result, these seeds will be spat out near the parent plant.
Type 3: Fruit/seeds with hook-like structure
The fruit/seeds with hook-like structure will cling onto the hair of the animal and will drop off further away from the parent plant when the animal moves around.
Thus, fruits/seeds dispersed by animals are typically dispersed in a random manner. (IMPORTANT!: Link-back Sentence!)
Method 4: Splitting/Explosive Action
Fruits/seeds dispersed by splitting typically have pod-like structures, which will split open when ripe.
Thus, fruits/seeds dispersed by splitting are clustered around the parent plant.
Here’s A Summary
By referring to the diagram of the parent plans and the seedlings provided in the question, we are able to use the scientific concepts that we’ve discussed to deduce what are the dispersal methods for the different plants in the question.
In my next article, I will be discussing the transport system in plants!
Stay tuned! 🙂