Investigation pertaining to plants

[dufka]

Hello my biology teacher gave us instructions related to the investigation. She said we have to do it during summer holidays. I am not sure which plant to choose. Please help me.

This is what she said:

The title of investigation: Influence of chosen factor on plant development

1) You must narrow/modify the topic given by choosing one factor, specific plant(s) and their stage of development

2) Define your resreach question and hypothesis

[Sandwich]

Have you done nothing related to this in your lessons? With those instructions, it sounds like you've done something similar to it (or read about it) already?

If not, just think of your factor and then think what would be the easiest plant to test it on. If you're going to do something relating to development, the obvious choice would be something cheap which grows very rapidly. Just think through it practically -- what sorts of things would be best for what you want to test? Then just use those criteria to select a plant species.

[dufka]

ohhh that's really helpful but could you give me an example?

[x___x]

You might want to choose an easy-to-manipulate factor like the volume/mass of water given to the plant. Another good idea is to choose different types of water from different sources and investigate whether the source of water has any effect on the rate of plant growth, but i guess in these kind of experiments, you have to measure the amount of nutrients/ organic matter that's found in the water, which might take long time/ effort to measure.

What about different types of soil? For this experiment you have to make the type of soil the independent variable, while the rate of the growth of the plant is the dependent variable. But in order to find out the rate, you have to measure the length of the plant over a set period of time.

Can you consider seed germination a type of plant development? If yes, you can carry out your experiment using seeds instead of already grown plants.

As you can see, there are so many ideas that you can use in order to design your own experiment. Try light intensity/ light colour (wavelength) as independent variables if you have the appropriate apparatus at school, so that you can conduct the experiment professionally.

Edited July 28, 2010 by x___x

[dufka]

Ohh thank you very much for your interesting ideas

The thing is that I have summer holiday now and I am supposed to conduct experiment during this time and I don't have professional apparatus. I'd like to investigate whether the light intensity has an effect on plant's growth but I don't have the faintest idea how to measure the amount of sun light (

I'd choose cardamine as a plant. What do you think? Is it a good idea? I thought about cardamine because it grows fast and it needs 2-3 days to germinate

[Sandwich]

Sounds like a good plant.

If you don't have the equipment for something, my suggestion is change what it is that you're measuring. Unless you can get hold of some light intensity measures! At IB it's a little too supposedly sophisticated to do just a plant in the light and a plant in the shade, so you would need to measure the light xP

[dufka]

but how am i supposed to measure light intensity?? I dont know how

[Sandwich]

Using a light intensity meter. Ask your teacher for one.

If you can't measure something, change your experiment.

[x___x]

Our school has a light sensor, so we could use it to measure light intensity. It was from PASCO or something like that. If your school doesn't have one ask them to purchase, if they can't afford it, then try to maybe change the independent variable. Why don't you try the wave lenght? Changing the wave length of the light to which you expose your sample plants will be a good idea for an experiment. If that doesn't suit you, then try to find an experiment which you know will give you results you can write about, discuss, and evaluate. Don't make your experiment too simple, and don't try to make it too complicated; after all, it's not a group 4 project or an extended essay.

You can ask your teacher for moderated lab reports from the teacher support material. They will help you with the reports write-up, which is more important than conducting the experiment, to tehh you the truth.

Good luck.