Following Meselson and Stahl’s work, investigators confirmed that other organisms also use semiconservative replication. There are, however, several different ways that semiconservative replication can take place, differing principally in the nature of the template DNA—whether it is linear or circular—and in the number of replication forks. Replicon and Origin of …

Translation takes place on ribosomes; indeed, ribosomes can be thought of as moving protein-synthesizing machines. A ribosome attaches near the 5′ end of an mRNA strand and moves toward the 3′ end, translating the codons as it goes. Synthesis begins at the amino end of the protein, and the protein …

The process of transcription is very similar in prokaryotes and eukaryotes, but there are major differences in the relation between the transcript and the mRNA used for polypeptide synthesis in eukaryotes. In prokaryotes, the immediate product of transcription (the primary transcript) is mRNA; by contrast, the primary transcript (also called …

The four bases in DNA – A, T, G, and C are sufficient to specify the 20 amino acids in proteins because each codon is three bases in length. Each sequence of three adjacent bases in mRNA is a codon that specifies a particular amino acid (or chain termination). The …

Arthur Cronquist was the Senior Curator of New York Botanic Garden and Adjunct Professor of Columbia University. He presented an elaborate interpretation of his concept of classification in The Evolution and Classification of Flowering Plants (1968), The further edition of his classification was published in “An Integrated System of Classification …

John Hutchinson was a British botanist associated with Royal Botanic Gardens, Kew, England. He developed and proposed his system based on Bentham and Hooker and also on Bessey. His phylogenetic system first appeared as “The Families of Flowering Plants in two volumes. The first volume contains Dicotyledons (published in 1926) …

Distribution of Microbes in Air No microbes are indigenous to the atmosphere rather they represent allochthonous populations transported from aquatic and terrestrial habitats into the atmosphere. Microbes of air within 300-1,000 or more feet of the earth’s surface are the organisms of soil that have become attached to fragments of …

Aeromicrobiology is the study of living microbes which are suspended in the air. These microbes are referred to as bioaerosols. Though there are significantly less atmospheric microorganisms than there are in oceans and in soil, there is still a large enough number that they can affect the atmosphere (like they …

Batch culture: A close system culture of algae in which there will be no supply or withdrawal of culture medium and biomass into or out of the culture vessel. In this type of culture the amount of medium and inoculum are known and specific. a. Lag phase It is the …

The culture of algae in the laboratory is not only important for knowing the details of the external morphology and reproduction in a particular algae or algal group, it is equally important to know the details of algal life histories, taxonomy, physiology, biochemistry, genetics and also its ultra-structure. Most of …