- Education and Science
Teaching Plant Biology to Kids I
Plant biology is rarely among the top 10 of the coolest topics that students enjoy learning, from high school up to university. I myself admit that during my high school years I considered plant biology boring, complicated, uninteresting, with nothing or very little happening … besides the fact that plant biology had a lot of chemistry in it or needed it in order to best understand it, which is true. Basically, I thought that only a nerd with nothing better to do would end up enjoying studying plants. Well, guess what, I ended up working with plants and really enjoying studying them! But, I wasn’t a nerd…I gues…Well, some call it karma….Looking back I agree that the traditional approach of teaching plant biology in most contexts may not be the best, especially if it is based on books and written material mainly with little or no lab work involving students. On the other hand, finding suitable material and experiments that keeps students interested and motivated can be a hard and challenging task. As we all know, plants do not move, do not make sounds, they hardly show any fast changes, and they are truly different from everything that we are more familiar and feel closest to about animals. Basically, they sit there still. Thus, it is not surprising that kids and teenagers feel plants boring and they “don’t explode” according to one of my students in science lab classes. I believe that the common prejudice and wrong ideas that students have about plant biology can be exceptionally modified, even overcome, if it is taught and well explained at younger classes. Here I will present the first set of some experiments that could be performed and taught in an entertaining as well as educating way to children from 2th to 6th grade, i.e. between the ages of 7 and 12. The design and materials selected are easily accessible, adjustable and suited for a typically equipped elementary/primary school and the experiments can also be performed at home for those families and enthusiastic parents who enjoy following their children learning processes more closely.
Together with the general science curricula followed in elementary/primary schools this experiments are meant for introducing science and the use of scientific knowledge to children. By making use of children’s natural curiosity about everything that surrounds them, it is expected that with experiments like these children become familiar with the scientific method. That is, to learn how to take notes and their importance, to make observations, to make measurements and develop the so called “eye for detail”. You will be surprised how much children can in fact notice and detect changes. Also, take this opportunity to teach children how to make hypothesis and train their critical thinking by discussing results and making conclusions. These experiments can be performed in succession and if so a term/semester should be chosen in which students can follow the changes in a plant’s life cycle. Also, adapt each experiment to the actual science knowledge/curriculum of the class(es) that you chose to start these experiments with. So, enjoy!
Where do Plants come from?
Activity 1: Seeds
Possibly the best way to introduce plants to children is answering this question: Where do plants come from? Start by discussing with them what they think a seed is; if helpful, by having them drawing their ideas and concepts. Ask them to bring seeds from home. Suggest the class to collect and bring as many different types of seeds as possible. If suitable, divide the class in groups or assign each student to bring a specific type of seed. Depending on your local availability (supermarket, garden, etc), common examples are: cereals (grains) (wheat, corn, barley, sorghum); stones (peach, almond, cherry, mango, avocado, plum); nuts (acorn, hazelnut, walnut, pine), beans (broad bean, bean, pea, lentil, lupin, peanut, soybean); and others like orange (or any citrine), sunflower, melon (or watermelon), grape, etc. Also, bring yourself your own seed collection with types/species that students may have difficulty finding or that are too exotic for students to see them as seeds like the second biggest of all seeds coconut. This activity is meant to introduce plant diversity to students through plant seeds.
- Discuss with students the different types of seeds by analyzing their main features such as: size, color, shape and texture.
- Have students group the different seeds according to those features and put results on a table.
- Afterwards, discuss with students if other criteria can be used to distinguish seeds, for example their mass. Use a weighing scale (a digital kitchen scale will do perfectly) to determine the mass of each seed presented. Use results to show students that not always the biggest size corresponds to the biggest mass.
- If students are well advanced in mathematics, possibly with 3rd or 4th grades, put students determining the mass of groups (samples) of seeds of the same plant species and use results to determine the average weight. Display results on a table and discuss with students the difference between individual mass of a seed and the average mass of seed. Discuss with students the importance of taking averages and the concept of independent measurements.
- Finally, as a suggestion, you can make a poster to hang on the wall with the different seeds studied grouped by types: grains, nuts, stones and beans.
Activity 2: How Do Plants Start Their Life?
The main goal of this activity is to understand how plants start their life by observing the changes that occur in seeds after they germinate and become little plants. Here children should acknowledge the importance of water in seed germination and learn that seeds are miniature plants in an embryonic state.
Seeds and Water
Most children are familiar with the preparation of food at home. Many of them have already observed that before being cooked some seeds that we eat (e.g. lentils, peas, beans, etc) are left in water for some time. Some of them have observed that some seeds go through noticeable changes when put in water, they swell, sometimes even burst, and they can also change color (usually becoming paler). Therefore, you should take this opportunity to discuss with children the different behavior that plant seeds show when put in water.
- Divide the students into groups, or if convenient assign individually, and ask them to gather some seeds of a given plant species and divide them into two groups A and B. Try to collect or arrange as many different plant species as possible
- Measure and take note of the mass of each group of seeds, or determine the seed average mass if appropriate. Seeds of group A will be put in a recipient with water, a glass will do just fine, filled about half its volume. Seeds in group B will be left in another recipient dry in contact with air and no water.
- Ask students to take notes and make observations of the changes that occur when seeds are put in water (group A) by comparing with seeds that left in no contact with water (group B). Instruct students to be observant as possible noting changes/events such as: do they fluctuate or sink to the bottom? Are there changes in color? Mass? Size? Do they get softer? Or nothing happens? Notes and observations should be registered after 1 hour, 3 hours, or at the end of the class, and the next day (roughly 24 hours after) and put them on a table.
- In the end, instruct students to determine the mass of the group of seeds A, or seed average mass if that was the case, and determine the gain in mass. Compare and discuss results of the different species studied. Students should conclude that seeds have different responses when in contact with water depending on the species.
- Take this experiment to show students how important it is to have a routine and follow a plan when performing scientific experiments. If you think this is boring ask students about what they think of this experiment. You will be surprised by their answers!
Discuss with students their ideas or observations that they might have on seed structure before stepping into the experiment. Have they observed/noticed structures inside a seed? For example seeds that we eat. From their ideas and previous knowledge about plants have them make their own hypothesis on trying to answer the question: What are plant seeds made of? In end they should understand that seeds are in fact plant miniatures.
- As with the previous experiment, divide the class into groups of 2 or 3 students and assign them seeds of different plant species, if possible. For convenience arrange large seeds, preferably from dicotyledons, like broad beans, previously embedded in water, in which the seed coat is easily removed without damaging the cotyledons or the embryo.
- Use a magnifying lens or a simple microscope, if possible, to observe the different components of a plant seed. Here, you may possibly have to assist students, depending on their age, after explaining them on how to remove the seed coat, and cut the seed in half in order to observe its structure.
- Along with the observations students should also take pictures, if possible, and make drawings of their own observations. Instruct students how to observe and collect the information required. It might be helpful at this point to give them a picture of the different components of a seed, for example bean, so that they know best what to look for.
- Compare the drawings/pictures collected by each group and have students conclude about the general structure of plant seeds among the different plant species. They should learn that seeds are made of cotyledons (in many species two) and an embryo, all involved by a seed coat. If possible, explore in more detail the structure of the embryo, namely: the radicle (embryonic root), the plumule (embryonic shoot) and the embryonic stem. Emphasize that these are all the main structures that will give rise and will be seen in a plant.
- You could use the main conclusions gathered to introduce the concept of a diagram and its importance to students, if this is the case.
- Use this experiment to show students how to plan and prepare a scientific experiment and the scientific method: make a hypothesis; draw an experimental plan and list all the materials and steps needed it; perform the experiment; collect results and make conclusions. Most importantly, success is not having the right an pretty data but mostly finding why you did wrong.
- You will notice that not all students know how to observe. They all know how to see and look at things. You see that it will not be easy, especially in bigger classes, and you will have to guide them through the observations and emphasize what they are looking for. Also, it is important to show students how important it is to take notes of every observation or idea that we might have while performing experiments, no matter how silly, unimportant, or out of context it may look like at first. First get notes of observations, facts and then discuss them in the end with your colleagues. It is important, especially with younger classes, not to be dismissive of their ideas and suggestions and take them as useful as possible.
- In addition, it may be that you will have to continue with the drawings, assembling of pictures and data collection into the next lesson. If that is the case, be sure to first do a review of what has been done previously and dedicate and use this second lesson to teach plant anatomy, use students notes as an exercise for training their writing skills and to present data. In addition, use their drawings as example of how art can help science and talk about scientific illustration by showing examples and talk its importance in scientific knowledge.
I suspect, and now this is my hypothesis, that this last experiment will probably be the experiment that they will enjoy most so far. However, I am sure that they will soon change their minds as they step into the next ones.
An example of an extraordinary seed
Meet the biggest of all plant seeds, coco de mer
Some reading that might be helpful:
- Teaching Plant Biology to Kids II
Plant biology is often seen by students as boring and complicated. Here we continue to explore more examples of how to teach and motivate school children into plant biology.
- Teaching Plant Biology to Kids III
Light and water are two of the most important factors that plants need in order to develop. Read about simple experiments and examples to teach kids how plants develop.
- History of Botany: Part 2, The Development of Taxono...
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