Plants and animals compete and cooperate in their environment resulting in what is often described as a "Balance of Nature" within an ecosystem. Organisms thrive or perish within biomes depending on their ability to adapt. In 1850, Charles Darwin published The Origin of the Species in which he postulated that all plants and animals originated with a single cell and over time has evolved into the complex number of species that we know today.
T. pallidum is one of the few human bacterial pathogens that have not been cultivated in vitro. This pathogens still remains the enigmatic pathogen, since few of its virulence factors have been identified and the pathogenesis of the disease is poorly understood.
Plants contain chemical compounds that may be in one way or another responsible for healing properties and other functions. Phytochemistry deals with the analysis of plant chemicals called natural products, and with changes occurring in such chemicals due to alterations in environmental conditions.
The diversity of species on Earth is incredible. There are more than 1.7 million species that have been discovered. Many species of plants and animals have evolved to depend on one another. For example, some plants can only be pollinated by a certain kind of bird or insect.
Xi shu (Camptotheca acuminata) belongs to the Nyssaceae family and is a huge tree growing up to a height of 25 meters having thin reddish-brown bark and a small number of branches close to its apex. In China people have named this tree as the happy tree owing to its effectiveness in treating a number of ailments and colds.