1. Nitrogen fixation is an essential process as the plants do not possess the tendency to use nitrogen in the form of N2. The bacteria known as nitrogen-fixing bacteria convert atmospheric nitrogen in the soil to ammonia, which can then be taken up by the plants.
2. The process of the water cycle is mainly driven by the energy provided by the Sun. This solar energy mediates the cycle by evaporating water from the lakes, oceans, rivers, and even the soil. Other water moves from plants to the atmosphere via the procedure of transpiration.
Evolution theory is a shortened form of the term "theory of evolution by natural selection," which was proposed in the 19th century by Charles Darwin and Alfred Russel Wallace.
