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
, US environment correspondent. Tuesday 23 August 2011 17.00 EDT First published on Tuesday 23 August 2011 17.00 EDT. Humans share the planet with as many as 8.7 million different forms of life, according to what is being billed as the most accurate estimate yet of life on Earth. Researchers who have analysed the hierarchical categorisation of life on Earth to estimate how many undiscovered species exist say the diversity of life is not equally divided between land and ocean. Three-quarters of the 8.7m species â the majority of which are insects â are on land; only one-quarter, 2.2m, are in the deep, even though 70% of the Earth's surface is water.