tetrahydrocannabinol (THC) [-hiâ²drÅkÉnabâ²inol] the active principle, occurring as two psychotomimetic isomers, in the hemp plant Cannabis sativa, used in the preparation of marijuana, hashish, bhang, and ganja. THC increases pulse rate and has variable effects on blood pressure.
Over the last 3.7 billion years or so, living organisms on the Earth have diversified and adapted to almost every environment imaginable. The diversity of life is truly amazing, but all living organisms do share certain similarities. All living organisms can replicate, and the replicator molecule is DNA. As well, all living organisms contain some means of converting the information stored in DNA into products used to build cellular machinery from fats, proteins, and carbohydrates. Three Domains of Life
Biodiversity is simply the variety of life on Earth, but its importance to global ecology has made it one of the most important concepts in modern science. Because biodiversity cuts across different levels of organization it is often useful to focus on a particular type of biological diversity. 1  Species diversity is a measure of how many different species are present in a given area. Most often when people think of biodiversity they think of species diversity. Genetic diversity measures the amount of inherited genetic variability contained within a populations of species.