1. Encouraging pupil questions
What makes plants so special? Two things. Almost all plants make their own food from water and a common gas in the air – carbon dioxide. The special green pigment, chlorophyll, traps the energy of sunlight, forming energy-rich carbohydrate. At the same time, plants release oxygen. People and animals would not exist if it were not for plants. This is why we should take plants more seriously!
A good starting point for exploring plants is to look at some of the simpler non-flowering plants. Simple plants do not have flowers, pollen or seeds; they reproduce in different ways. This group of plants includes mosses, ferns and lichen. Resource 1: Looking at plants has more information about these simple plants.
Do you have examples of these in your local environment?
On your usual walks, try to find examples of these different plants; this will give you ideas for questions to raise with your pupils. You could collect some to bring into your class.
Case Study 1 shows how one teacher encouraged his pupils to observe these simple plants and Activity 1 shows how you can support your pupils to ask their own questions about them.
Case Study 1: Local simple plants
Mr Karume and his class in Tanzania walked round the area near their school, hunting for examples of simple plants. They found tiny mosses, green tufts growing on the bark of the shady side of tree trunks and rocks. They looked at lichen, which grew on the bark of the sunny side of tree trunks and rocks and even roofing. They found small ferns growing in cracks in the wall near the rainwater tank. They drew each plant and noted where it was growing.
When they were back in the classroom, Mr Karume asked his pupils to think about how these plants were able to reproduce. He displayed all their ideas on newsprint round the classroom.
To find out more, the pupils collected some moss and grew it under the bottom half of a clear plastic bottle. After a time, they noticed that the moss produced green, club-shaped capsules that turned brown and split, releasing tiny spores. They discussed whether these would grow into new moss.
The pupils then went back to observe the ferns and the lichen. They discovered that all the ferns had patches of scaly brownish spore capsules on the undersides. They kept observing the lichens, but saw no spore production. Mr Karume asked a local high school biology teacher to tell them more about lichen and how it reproduces. He was very pleased with how these activities had increased his pupils’ awareness of these plants.
Activity 1: Asking questions
Freshwater algae are plants that make food and give off oxygen. Grow some algae in the classroom by letting some water turn green in a clear open glass (or collect some algae locally).
- Encourage pupils, working in small groups, to think of questions to ask about the algae. What would they like to know about it? Remind your pupils of the seven characteristics of living things. Does it need light to grow? Where does it come from? Why is it important? Each group of pupils should record each question on a piece of paper or newsprint.
- Ask each group in turn to share their questions. Display the questions in suitable clusters on the classroom wall and discuss them. Which questions could you investigate? Which do you need to look up in a book or ask an expert or use the Internet? Which might be very difficult to answer?
If you have time, ask the groups to carry out investigations (see Key Resource: Using investigations in the classroom [Tip: hold Ctrl and click a link to open it in a new tab. (Hide tip)] ) and do research to answer some of the questions.
Section 2 : A closer look at plants
2. Observing plants