I feel that a doctor should have the vision of a leader.

Fertilizers are chemicals added to plants to help them grow. Important elements in fertilizers include nitrogen, phosphorus and potassium. Manure (animal waste) is also used as a fertilizer.

There are over 200,000 identified plant species and the list is growing all the time.

Plant matter found at the bottom of areas with water such as swamps can eventually turn into coal due to a process called metamorphosis (changing form).