From seed to tree

This is an acorn. How can you make an oak out of this acorn? In order to make a plant, you need a few different ingredients: Water, Sun-energy, Carbon Dioxide, Nitrogen Phosphorous... and minerals. Let's get going!

Start with a glass bottle, fill it with water place the acorn in the mouth. And turn on the sun! Something starts happening inside the acorn. The first root grows, the primary root, and then the first leaves, the cotyledons unfold. Inside the acorn there is a store of nutrients, called the endosperm, which feeds the sprouting plant during the first stage.

But after a while, the endosperm is used up, and the plant has to get its nutrients some other way. Unlike us, plants produce their own food. But for this to happen, we need some components: You already have three of them -- water, sun-energy, and carbon-dioxide -- but you need a few more. You have probably seen, or caught the smell of fertilizers that have been sprayed on fields. The fertilizers mainly consist of nitrogen and phosphorus, and without these elements the plant cannot grow.

The plant also needs some minerals, but most of these occur naturally in the soil. Look what happens when you add some fertilizer to your oak! Now things start happening! The plant starts making its own food. In the cells of the green leaves, there are energy factories called chloroplasts.

Inside the chloroplasts, the plant combines carbon dioxide from the air and water from the ground with the force of sun energy to make a sugar called glucose. Meanwhile, oxygen is formed and released into the air. And this is the process called photosynthesis! Glucose is the plant's food. And just like us, the plant needs food in order to get energy for growth.

So during day the plant focuses on producing food. During the night the focus shifts to growing. The energy in the glucose is now put to use. To release the energy again, the glucose is broken down into its parts. Inside the plant's cells, oxygen molecules are used to separate the glucose into carbon dioxide, water and energy.

This is photosynthesis in reverse: The cells are breathing and it's called cellular respiration. It happens in all cells, including yours! With this released energy the plant can grow bigger, form buds, and build seeds. But, if you want your oak to grow into a truly mighty tree, you have to plant it in some suitable meadow... ... so that the oak gets proper space to spread its roots!