Water: Water is a transparent and nearly colorless chemical substance that is the main constitute of Earth’s streams, lakes, oceans and the fluids of most living organisms. Resource: A resource is any physical material constituting part of Earth that people need and have value. Natural materials become resource when humans …

The term ‘ecosystem’ was first used by A. G. Tansley in 1935. Tansley defined an ecosystem as a particular category of physical systems, consisting of organisms and inorganic components in a relatively stable equilibrium, open, and of various sizes and kinds. An ecosystem is a structural and functional unit of …

Wood is a porous and fibrous structural tissue found in the stems and roots of trees and other woody plants. It is an organic material – a natural composite of cellulose fibers that are strong in tension and embedded in a matrix of lignin that resists compression. In this article, Internal structure of Wood …

Global Radiation Balance There are various factors that influence the amount of radiation coming from the sun to the earth’s surface. Some of the radiation is reflected upward, some is scattered both upward and downward directions. Besides, some of the radiation is absorbed by the clouds and atmosphere. The rest …

Arsenic is a naturally found chemical element whose atomic number is 33 with a symbol as ‘As’. It occurs in many minerals, usually in combination with sulfur and metals, but also as a pure elemental crystal. Arsenic is one of the fundamental chemical element. It is a metalloid. Symbol: As …

Toxicity is the degree to which a substance can damage an organism. Toxicity can affect a whole organism, such as an animal, bacterium, or plant, as well as a cell (cytotoxicity) or an organ such as the liver (hepatotoxicity). Toxicity effects are dose-dependent; so, even water can lead to water …

Anomalous secondary growth” is the term under which have been grouped cambial conformations, cambial products, and cambial numbers which differ from the most common “normal” condition, namely, a single cylindrical cambium that produces phloem externally and xylem internally. In this article, Anomalous secondary growth, it’s causes and position will be …

Periderm is the corky outer layer of a plant stem formed in secondary thickening or as a response to injury or infection. It is a cylindrical tissue that covers the surfaces of stems and roots of perennial plants during early secondary growth; therefore it is not found in monocots and …

The marine environment is an essential component of the global life-support system. Marine environment is different from the terrestrial and freshwater aquatic environment having high salt concentration. Its water covers approximately 71% of the earth’s surface. This is equivalent to 361 million sq. kilometers (139 million sq. miles). Average depth of …

Do you ever  dig down deep into any soil? If you did so, you may have followed different colors and layers in there. These layers are called horizons in soil science. The idea of Horizon and Soil Horizons are slightly different. Horizon is a distinct layer of soil, approximately parallel …