Picaridin repels insects, ticks and chiggers. It is a synthetic compound first made in the 1980s. It was made to resemble the natural compound piperine, which is found in the group of plants that are used to produce black pepper. Picaridin has been widely used as an insect repellent in Europe and Australia, but has only been available in the United States since 2005.
Plants have run the biological carbon cycle for 3 billion years in the ocean, and for the past 400 million years on land, using the process of photosynthesis to convert atmospheric CO2 into carbon-rich carbohydrates and sugars to feed themselves. And they are very good at it.
Leaf-A plantâs leaves collect sunlight for the process of photosynthesis. Photosynthesis is the process where green plants use sunlight, carbon dioxide and water to make food and oxygen. Little openings in the leaves, called stomata, collect carbon dioxide from the air and release oxygen.