Tropical Rainforest Regions

Tropical Rainforest Regions Tropical rainforests mainly occur in the Worlds equatorial regions. Tropical forests are restricted to the small land area between the latitudes 22.5 ° North and 22.5 ° South of the equator - between the Tropic of Capricorn and the Tropic of Cancer (see map). They are also located on major separate continental forests which preserve them as independent, non-contiguous realms. Rhett Butler, on his excellent site  Mongabay, refers to these four regions as the Afrotropical, the Australian, the Indomalayan and the Neotropical rainforest realms. The Afrotropical Rainforest Realm Most of the tropical rainforests of Africa exist in the Congo (Zaire) River Basin. Remnants also exist throughout Western Africa which is in a sorry state due to the plight of poverty which encourages subsistence agriculture and firewood harvesting. This realm is increasingly dry and seasonal when compared to the other realms. The outlying portions of this rainforest region are steadily becoming desert. FAO suggests this realm lost the highest percentage of rainforests during the 1980s, 1990s, and early 2000s of any biogeographical realm. The Australian Oceanic Pacific Rainforest Realm Very little of the rainforest is located on the Australian continent. Most of this rainforest is located in Pacific New Guinea with a very small portion of the forest in the Northeast of Australia. Actually, the Australian forest has expanded over the last 18,000 years and remains relatively untouched. The Wallace Line  separates this realm from the Indomalayan realm. Biogeographer Alfred Wallace marked the channel between Bali and Lombok as the divide between two great zoogeographic regions, the Oriental and Australian. The Indomalayan Rainforest Realm Asias remaining tropical rainforest is in Indonesia (on scattered islands), the Malay peninsula and Laos and Cambodia. Population pressures have dramatically decreased the original forest to scattered fragments. Southeast Asias rainforests are some of the oldest in the World. Studies have indicated that several have existed for over 100 million years. The Wallace Line separates this realm from the Australian realm. The Neotropical Rainforest Realm The Amazon River Basin covers some 40% of the South American continent and dwarfs all other forests in Central and South America. The Amazon rainforest is roughly the size of the forty-eight contiguous United States. It is the largest continuous rainforest on Earth. The good news is, four-fifths of the Amazon is still intact and healthy. Logging is heavy in certain areas but there is still debate over the adverse effects but governments are involved in new pro-rainforest legislation. Oil and gas, cattle and agriculture are major causes of neotropical deforestation.

plaque assay essays

plaque assay essays Title: Exercise Seven Plaque Assay for Determination of Phage Titre One of the most numerous microorganisms known to man is viruses and these acellular agents can infect all types of cellular organisms. Viruses are considered infectious elements that contain a single type of nucleic acid but require a host cells metabolism to replicate. They are typified by both an extracellular state and an intracellular state. (Madigan et al, 2003; Prescott et al, 2002). The classification of viruses can be extended further, by focusing on a specific group known as Bacteriophages. These are viruses that infect bacterial cells and use them as their host. Those viruses that infect Eschericha coli are known as Coliphages and are identified by type numbers ie. T2, T4 and T7. (Prescott et al, 2002; Reddy, 2002). Temperate bacteriophages not only infect bacteria but can also establish a lysogenic relationship rather than immediately lysing their hosts. The DNA of the invading phage has two possible fates: reproduction leading to generation of new phage particles and lysis of the cell or integration into the host chromosome. Here it is replicated passively with the host DNA a process known as lysogeny. Some coliphages (although not exclusively) are temperate bacteriophages. (Lehninger et al, 1992; Madigan Despite the diversity in viral structures, most viruses complete similar stages in the viral lifecycle. Excluding the lysogenic pathway for the moment, a typical viral lifecycle can be categorized into five stages: 2. Penetration: by either the whole virion or just the nucleic acid 3. Synthesis of nucleic acid and proteins: where the hosts metabolism is utilized 4. Assembly: of structural subunits and packaging It should be noted that these are generalized stages and that viruses go about a ...

The Conservation of Non-Living Elements and Living Natural Resources Essay

The Conservation of Non-Living Elements and Living Natural Resources - Essay Example Albert Einstein is regarded as one of the greatest modern scientists. Albert EinsteinPredictably and prophetically remarked that the disappearance of honeybee for more than 5 years can pose threat to the survival of mankind. Every single living and non-living animal special plays a pivotal role in the production of vegetables and fruits that are consumed by human beings. An article outlined by Newsweek based on loss of bee and called it an urgent crisis. According to the United States Department of Agriculture, a survey has been done to provide vivid information about the adverse impact of the loss of honeybee. The loss of third of commercial bees has been the prime cause behind the introduction of the emergency plan. Over the last fifty years, the population of the honeybee has been lessening. The Department of Agriculture stated that honeybee helps to pollinate more than 80 percent of the flowering crops (McCarthy 90). Furthermore, this process of pollination leads to one-third of every food people eat. The loss could not only affect the dairy and beer industries but may threaten dietary fruits and vegetables such as broccoli, apples, cucumbers, asparagus, nuts and strawberries. The executive of the Consumer Wellness Center, Mike Adams stated that the loss of population of the human bee is one of the greatest fears to the future of the planet. The rapid upsurge of the population has been one of the pivotal reasons behind the loss of honeybees. The positive impact of honeybees towards mankind cannot be denied. But it is vital for the government to take necessary steps to mobilize the problem. According to the State Beekeepers Association of California, there is no danger of extinction of honeybee species. The extinction of these species would take hundreds of years.