Resource 2: Understanding plants

This activity will give you the opportunity to see whether you have any misconceptions, and to learn more about the misconceptions that are commonly held by others.

What do you know about plants? The following questions will help to you to find out.

Here are some statements about plants. Are they true or false?

1. A plant uses carbon dioxide at night.
2. Plants carry out one process during the day and a different one at night.
3. Carbon dioxide is used in plants for the same purpose as oxygen is used in animals.
4. Part of the plant’s food is sunlight.
5. Plants feed on sugars in the soil.
6. Plants give out oxygen.
7. Plants give out carbon dioxide.
8. Plants use oxygen during the daytime.
9. Plants use carbon dioxide during the daytime.
10. Carbon dioxide and water are a plant’s food

Answers

1. False: Plants use carbon dioxide in order to produce ‘food’ (glucose) through the process of photosynthesis. In order to do this the plants need sunlight (ultraviolet radiation).
2. False: The common misconception is that plants undergo photosynthesis in the day and respiration at night. Like all living things they undergo respiration all the time. Respiration is the process through which stored food is converted into the energy that living things require to stay alive.
3. False: This misconception arises because plants are often thought to be the opposite to animals.
4. False: Children have a very human-centred view of food and nutrition, therefore anything the plant uses or takes in is regarded as food.
5. False: It is a widely held misconception that plants take in their food from the external environment like animals do. After all, you can buy bottles of plant food in the shops! Plants getting sugars from the soil is a hybrid between this misconception and the idea that the plant’s food is glucose.
6. True: Oxygen is a by-product of photosynthesis and is given out through small holes on the underside of the leaves called stomata.
7. True: Plants are constantly respiring and carbon dioxide is a waste product of respiration. Both photosynthesis and respiration occur simultaneously during daylight, but there is a net input of carbon dioxide and net output of oxygen.
8. True: Plants use oxygen for respiration
9. True: Plants use carbon dioxide for photosynthesis
10. False: Children have a very human-centred view of food and nutrition and therefore anything the plant uses or takes in may be regarded as food. They may find it hard to understand that plants manufacture their own food (glucose) from CO₂ and water.