The primary aim of culture preservation is to maintain the organism alive, uncontaminated, and without variation or mutation, that is, to preserve the culture in a condition that is as close as possible to the original isolate. Once a microorganism has been isolated and grown in pure culture, it becomes …

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 …

Selecting University is a crucial step in the journey of Higher Studies. This post is mainly for those who will prefer to apply centrally for admission to US universities. But others can find the ways of selecting Universities  useful too.   The post is from a graduate student at the …

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 …

In the experiment, we measure the two continuous characters which are associated with each other. For example, the height of the plant and the temperature of the atmosphere. Accordingly, to understand the relationship between two such variables, we need to know how they are related and how the relationship can …

We can test the significance of the two sample means by using a t-test. However, in cases where there are more than two samples, it is done by Analysis of Variance (ANOVA). This method is carried out by comparing sample variances using Variance Ratio Test or F test. So at …

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 …

Flagella Most prokaryotes are motile by swimming, and this function is typically due to a structure called the flagellum. The plural form of this word is flagella which means whip. Bacterial flagellum is a threadlike locomotor appendages extending outgrowth from the plasma membrane and cell wall. Bacterial flagella are thin, …