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Plants appeared on land about 425 million years ago and the evolutionary history of the plant kingdom reflects increasing adaptation to the terrestrial environment. Plants have organs and organ systems.
This organism is widespread in the environment, but rare in the flora of healthy individuals. Its carriage increases with hospitalization.
Process by which an early metazoan embryo becomes a gastrula, acquiring first two and then three layers of cells.
Three different prokaryotic DNA polymerases are known, of which DNA polymerases I and II are meant for DNA repair and DNA polymerase IN is meant for actual DNA replication
Coenzymes are small organic molecules that function with thousands of different enzymes in all organisms, assisting in the catalytic processes needed for life. They often contain vitamins as components.
A tissue is a group of similar cells (together with associated cell products) specialized for the performance of a common function.
Microalgae and macroalgae have been utilized by man for hundreds of years as food, fodder, remedies, and fertilizers. Ancient records show that people collected macroalgae for food as long as 500 B.C. in China and one thousand of years later in Europe.
The area of developmental genetics has also received major attention of geneticists in recent years to answer questions like the following. What are the relative roles of nucleus and cytoplasm in differentiation?
Mutations are heritable changes in the genetic material that give rise to alternative forms of any gene. These alternate forms are called alleles. There are two broad types of mutations, those that affect the gene and those that affect whole chromosomes (
In botany, a herbarium is a collection of preserved plant specimens. These specimens may be whole plants or plant parts: these will usually be in a dried form, mounted on a sheet, but depending upon the material may also be kept in alcohol or other preser
Among all living organisms, flowers, which are the reproductive structures of angiosperms, are the most varied physically and show the greatest diversity in methods of reproduction of all biological systems.
Germplasm theory of Weismann was a very significant advancement in our understanding of heredity, since this was for the first time that a distinction between hereditary and environmental variations could be made on a sound basis.
Discoveries in molecular biology have allowed scientists to duplicate natural genetic transfer phenomena in the laboratory and to develop methods to introduce almost any type of genetic information into an organism.
Column chromatography is one of many forms of chromatography. Others include paper, thin-layer, gas, and HPLC. Most forms of chromatography use a 2-phase system to separate substances on the basis of some physical-chemical property.
Alkaloids are classified according to the amino acid that provides both the nitrogen atom and the fundamental portion of the alkaloid skeleton, and these are discussed in turn.
The Chloroflexi (Chlorobacteria) are a class of bacteria that produce energy through photosynthesis. They make up the bulk of the filamentous anoxygenic phototrophs
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