Measuring Photosynthesis

Thursday November 30, 2017

Here’s a neat experiment you can do to measure the rate of photosynthesis of a plant, and it’s super-simple and you probably have most of what you need to do it right now at home!


You basically take small bits of a leaf like spinach, stick it in a cup of water that has extra carbon dioxide in it, and shine a light on it. The plant will take the carbon dioxide from the water and the light from the lamp and make oxygen bubbles that stick to it and lift it to the surface of the water, like a kid holding a bunch of helium balloons. And you time how long this all takes and you have the rate of photosynthesis for your leaf.


Here are the steps for the experiment:


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What Color Light Do Plants Like Best?

Tuesday August 23, 2011

If you’re thinking sunlight, you’re right. Natural light is best for plants for any part of the plant’s life cycle. But what can you offer indoor plants?


In Unit 9 we learned how light contains different colors (wavelengths), and it’s important to understand which wavelengths your indoor plant prefers.


Plants make their food through photosynthesis: the chlorophyll transforms carbon dioxide into food. Three things influence the growth of the plant: the intensity of the light, the time the plant is exposed to light, and the color of the light.


When plants grow in sunlight, they get full intensity and the full spectrum of all wavelengths. However, plants only really use the red and blue wavelengths. Blue light helps the leaves and stems grow (which means more area for photosynthesis) and seedlings start, so fluorescent lights are a good choice, since they are high in blue wavelengths.


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Giant Veggies!

Monday August 22, 2011

Six-foot zucchini? Ten-foot carrots? Are giant veggies just a photography trick, or are they real?


The happy news is that yes, they’re real! Expert horticulturists have accumulated a great wealth of knowledge about different climates and dirt conditions. They must know about the different chemical, physical and biological properties of gardens and do multiples of experiments dozens of plants. We found an incredible horticulturist, John Evans, who has accumulated over 180 first places in both quality and giant vegetable categories, with 18 State and 7 World Records.


According to John Evans: “If you could, imagine what it would be like to dig up a carrot from your garden and not knowing how big it is until the last minute, and then finding out that it’s 19 lbs. Now that’s exciting!”


John has spent many years developing fertilizers, bio-catalysts, and growing techniques to grow 76-lb cabbages (photo shown left), 20-lb carrots, 29-lb kale, 60-lb zucchini,  43-lb beets, 35-lb broccoli and cauliflowers, and 70-lb swiss chard that was over 9 feet tall and took three people to carry it to the trailer!


Here’s a video on growing giant flowers by a passionate community gardening club:
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Stomata

Monday August 22, 2011

When we think about the parts of plants, we often thing about stems, leaves, seeds, or flowers. Many plants have these parts. However a plant does not need to have any of these parts to be considered a true plant. So, instead of talking about parts that all plants have, we’ll talk about parts that some plants have. Then, as we talk about different groups of plants, we’ll talk about which parts they do or do not have.


Many plants have a waxy layer called a cuticle. The cuticle helps keep water in the plant, and prevents water loss. However, the cuticle also keeps gases from entering or exiting the plant.


This is a pretty big problem, when you think about how important photosynthesis is in plants. Remember that in photosynthesis, carbon dioxide has to come in and oxygen has to go out. So, plants have small openings called stomata. Stomata can open when the weather is cool to allow gases in and out. When the weather is hot, stomata close up, conserving water and keeping it from escaping.


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How to Ripen a Tomato with a Banana

Monday August 22, 2011

It drives me crazy it when my store-bought tomatoes go straight from unripe to mush. After talking with local farmers in my area, I discovered a few things that might help you enjoy this fruit without sacrificing taste and time.


Grocery store owners know that their products are very perishable. If the tomatoes arrive ripe, they might start to rot before they can get on the shelf for the customer. Ripe tomatoes are near impossible to transport, which means that farmers often pick unripe (green and therefore very firm) tomatoes to put on the truck. Grocery stores prefer hard, unripe tomatoes so their customers can get them home safely.


The problem is, how do you enjoy a tomato if it’s not ready?


Scientists and food experts ripen tomatoes quickly with ethylene while they are in storage. As the gas surrounds the green tomato, it chemical reacts to speed up the ripening process, causing the tomato to soften and change color to red or orange.


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Plant Press

Sunday August 21, 2011

Art and science meet in a plant press. Whether you want to include the interesting flora you find in your scientific journal, or make a beautiful handmade greeting card, a plant press is invaluable. They are very cheap and easy to make, too!


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Monocots and Dicots

Saturday August 20, 2011

Flowering plants can be divided into monocotyledons and dicotyledons (monocots and dicots). The name is based on how many leaves sprout from the seed, but there are other ways to tell them apart. For monocots, these will be in multiples of three (wheat is an example of a monocot). If you count the number of petals on the flower, it would have either three, six, nine, or a multiple of three. For dicots, the parts will be in multiples of four or five, so a dicot flower might have four petals, five petals, eight, ten, etc.


Let’s start easy…grab a bunch of leaves and lets try to identify them. Here’s what you need to know:


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Einstein’s Garden

Saturday August 20, 2011

Mass and energy are conserved. This means you can’t create or destroy them, but you can change their location or form.


Most people don’t understand that the E energy term means all the energy transformations, not just the nuclear energy.


The energy could be burning gasoline, fusion reactions (like in the sun), metabolizing your lunch, elastic energy in a stretched rubber band… every kind of energy stored in the mass is what E stands for.


For example, if I were to stretch a rubber band and somehow weigh it in the stretched position, I would find it weighed slightly more than in the unstretched position.


Why? How can this be? I didn’t add any more particles to the system – I simply stretched the rubber band. I added energy to the system, which was stored in the electromagnetic forces inside the rubber band, which add to the mass of the object (albeit very slightly). Read more about this in Unit 7: Lesson 3.


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Carnivorous Greenhouse

Saturday August 20, 2011

Plants need light, water, and soil to grow. If you provide those things, you can make your own greenhouse where you can easily observe plants growing. Here’s a simple experiment on how to use the stuff from your recycling bin to make your own garden greenhouse.


We’ll first look at how to make a standard, ordinary greenhouse. Once your plants start to grow, use the second part of this experiment to track your plant growth. Once you’ve got the hang of how to make a bottle garden, then you can try growing a carnivorous greenhouse.
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The Science of Broccoli

Saturday August 20, 2011

Broccoli, like all plants, has chlorophyll, making it green. You can really “see” the chlorophyll when you boil broccoli. This is such a simple experiment that you can do this as you prepare dinner tonight with your kids. Make sure you have an extra head of broccoli for this experiment, unless you really like to eat overcooked broccoli.

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Turning Compost into Gold

Sunday July 24, 2011

If you have a backyard garden, be sure to give it plenty of sunshine, water, and garbage.


Wait… garbage?  Yes, you read that right.


Garbage like rotting food and coffee grounds, made into compost, can be highly beneficial to garden plants.  Why? It all has to do with nitrogen.


Plants need nitrogen in order to survive.  There is plenty of nitrogen in the atmosphere; the problem is that plants can’t use it in the form found in the atmosphere.  For this, bacteria are needed.  Bacteria “fix” nitrogen, meaning that they change it into a usable form.


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Keep your compost heap moist, but not soggy and turn it with a pitchfork or spade to add air into the mix.  Once your compost bin is going strong, you can add it to your garden for improved plant growth!


Three Ways to Create a Plant

Sunday July 24, 2011

If you’ve ever eaten fruits or vegetables (and let’s hope you have), you have benefited from plants as food.  Of course, the plants we eat have been highly modified by growers to produce larger and sweeter fruit, or heartier vegetables.


There are three basic ways to create plants with new, more desirable traits:


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