Question 1 - Why do plants grow?
Everything on Earth has a purpose. A plant's purpose is to help produce oxygen, and help keep us, and other species around the world alive. All species work together to help keep Earth in balance in life cycles, these cycles all connect to each other!
Question 2 - How does a plant produce oxygen?
A plant produces oxygen by using a life cycle called photosynthesis. This life cycle starts with the plant, it absorbs energy from the sun, and turns it to its own sugar for energy. Using that energy to power the plant's chloroplast, it takes in carbon dioxide that we breath out, and comes out as oxygen all of this less than a few seconds.
Question 3 - What is in soil, that helps plants grow?
Soil has three main functions in a garden: to anchor plant roots, supply water and provide minerals. Plant roots take up nutrients and use them to grow and produce plants. The most fertile topsoil has a dark, rich color, indicating the presence of humus. Soil absorbs some of the rainwater that falls, holding it as a film surrounding each individual particle. A soil's water-holding capability varies by soil type, with heavy clay soils being the most water retentive and sandy soils being the most porous and draining quickly.
I hope this helps! I worked hard on it, sorry this is like a year late, but for all of you just looking it up now, here ya go! :)