Biodiversity is the variation in living organisms, viewed within a given habitat, ecosystem or in the world as a whole. The concept is usually applied to the species diversity, although the notion of genetic biodiversity is applied to the variation in genes within an individual species. While most people think of rainforests as loci of great biodiversity, biomes such as oceans and grasslands are the likely repositories for even greater variation. Retention of diverse biota is important, since intact ecosystems are thought to be essential for provision of ecosystem services to humans, including maintenance of a diverse foodbank, pollination, clean water, flood control, pest control, waste decomposition, biomass energy resources and climate stability. Biodiversity is presently critical since we live in the era of the Mass Holocene Extinction, a period of species loss caused by man, and unrivaled in rate of species loss. Although the number of total species numbers in the tens of millions, most have not yet even been described. The extinction of a species is almost always related to destruction of habitat or man-made pollution.
The Permian period lasted from 290 to 248 million years ago and was the last period of the Paleozoic Era. The distinction between the Paleozoic and the Mesozoic is made at the...
Ecoregions of BangladeshLast Updated on 2014-10-19 17:45:45Bangladesh has five ecoregions:
Sundarbans freshwater swamp forests
Lower Gangetic Plains moist deciduous forests
Mizoram-Manipur-Kachin rain forests
Myanmar coastal rain forests
The ecoregion lies in the vast delta formed by the confluence of the Ganges, Brahmaputra, and Meghna rivers. The maze of mangrove channels extends across southern Bangladesh and India's West Bengal State.The Sundarbans Mangroves ecoregion is the world's largest mangrove ecosystem.
Named after the dominant mangrove species Heritiera fomes, locally known as sundri, this is the only mangrove ecoregion that harbors the Indo-Pacific region's largest predator, the tiger (Panthera tigris).
Unlike in other habitats, here tigers live and swim among the mangrove islands, where they hunt scarce prey such as chital deer (Cervus axis), barking deer (Muntiacus muntjak), wild... More »
Big Bend National Park, United StatesLast Updated on 2014-10-19 16:55:59Big Bend National Park is one of the two National Parks located in the state of Texas, in the USA. Big Bend National Park is located in the Big Bend region along the border of Texas and Mexico where the Rio Grande bends toward the Gulf of Mexico.
Because the park contains a variety of habitat types including mountains, deserts, and riparian habitats, the park is home to a diverse flora and fauna. Visitors arrive at Big Bend National Park to hike, camp, watch wildlife, and experience the river by rafting or canoeing.
Big Bend National Park is located in the big bend of the Rio Grande along more than 161 kilomters (100 miles) of the Texas-Chihuahua-Coahuila border southeast of El Paso, Texas in Brewster County, Texas. It includes a large portion of the Chihuahuan Desert as well as the Chisos Mountains on the Texas side of the Rio Grande’s expansive steep canyons.
In 1933,... More »
PlantLast Updated on 2014-10-19 16:48:46
A plant is any one of the vast number of organisms within the biological kingdom Plantae; in general, these species are considered of limited motility and generally manufacture their own food. They include a host of familiar organisms including trees, forbs, shrubs, grasses, vines, ferns, and mosses. Conventionally the term plant implies a taxon with characteristics of multicellularity, cell structure with walls containing cellulose, and organisms capable of photosynthesis. Modern classification schemes are driven by somewhat rigid categorizations inherent in DNA and common ancestry.
Throughout most of the history of science from Aristotle to Linnaeus and into the 20th century, species were divided into two kingdoms: animals and plants. Driven by DNA characterizations and other modern analysis, fungi and bacteria have now been removed to separate kingdoms; in particular,... More »
MammalLast Updated on 2014-10-15 22:58:09
Mammalia is a group of warm-blooded, air breathing vertebrates. With the common name mammal, each species is endowed with the characteristic of fur and three-boned middle ear; but the most remarkable element of group identity is an advanced brain element known as the neocortex, that functions as a center of complex cognition; no species except mammals have this well defined brain structure. Having pronounced inherent sexual dimorphism, the females have mammary glands capable of producing milk. There are approximately 5400 described mammalian species comprising around 1200 genera.
Mammals span a size range from the three centimeter Bumblebee Bat to the 33 meter long Blue Whale. Feeding habits vary widely among species, including carnivores and insectivores who prey on animals, to frugivores and granivores who eat fruit or seeds. Earliest mammals arose approximately 200 to 130... More »
BacteriaLast Updated on 2014-10-12 18:54:28
Bacteria are any of a very large group of single-celled microorganisms that display a wide range of metabolic types, geometric shapes and environmental habitats—and niches—of occurrence. Normally only several micrometers in length, bacteria assume the form of spheres, rods, spirals and other shapes. Bacteria are found in a very broad gamut of habitats; for example, bacterial extremophiles that thrive in such places as hot springs, arctic environments, radioactive waste, deep sea oil seeps, deep Earth crustal environments, hypersaline ponds and within other living organisms. There are approximately 50 million bacterial organisms in a single gram of typical surface soil. The worldwide bacterial biomass exceeds that of all plants and animals on Earth. However, the majority of bacteria have not yet been characterised,
Bacteria are members of the prokaryote... More »
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