Sourav Pan is the founder and sole author of Biology Notes Online. He holds a Bachelor of Science (B.Sc.) degree and an M.Sc. in Microbiology from the University of Calcutta. He creates educational resources covering microbiology, immunology, biotechnology, genetics, cell biology, botany, zoology, and other life-science subjects.
His goal is to make complex biological concepts easier to understand through well-structured, student-friendly articles based on academic textbooks, peer-reviewed research, and authoritative scientific sources. In addition to writing new content, he regularly reviews and updates articles to improve their accuracy, clarity, and educational value.
What are plasmids? Copy Number and Physical Nature of Plasmids Properties of Plasmids Plasmid Replication Mechanism 1. Rolling circle Mode of Replication Rolling-Circle Replication (RCR) is described as a method of DNA replication that is used by some viruses, plasmids and circular genetic elements. A single-strand nick is introduced at the origin and the 5′-end … Read more
Microorganisms are everywhere in their the distribution. In any given environment, many microorganisms are present at any given time. It is difficult to identify a specific kind of microbe until we understand their ecological needs. For instance, anaerobic microbes do not require oxygen those that are aerobic require oxygen micro-aerophiles to have oxygen however, in a small amount. So, we require cotton plugs to provide an conditions that are aerobic and keep the growing culture uninvolved with unwanted microbes. Cotton plugs are made of cotton along with air pours. Air can flow through air pours, but not the bacteria that cause microbial contamination. They are fixed to the surface of cotton fibres , and prevent them from being able from getting into flasks, tubes, etc. Air aids in for the development of microorganisms within glass equipment.
What is genetic variation? Genetic variation is the differences that are found in the DNA sequences among individuals of the same species. It’s what makes every organism a bit different from others even they belong to same population. Inside populations, variation is mostly caused by mutations, recombination / crossing over (during meiosis), and sometimes by … Read more
What is Artificial Selection? Artificial selection is a process by which humans are intentionally choosing certain organisms / traits for reproduction, it has been used for centuries actually even before the mechanism of genes was understood properly. In artificial selection, individuals that show desirable features (like color, yield, behavior etc.) are allowed to breed, while … Read more
DNA replication is the process by which genetic material is copied before cell division happens, it’s considered essential for inheritance. Among different models, the main ones observed are Theta model, Rolling Circle model, and Linear DNA replication. Each model are used by different organisms or DNA types (like plasmids, viruses, or eukaryotic chromosomes). The three … Read more
An codon chart is presented as a compact key, that maps three-nucleotide codons to amino acids, and it is usually shown as a table or circular map. In the chart, each codon is represented by three bases (A, U, G, C) and is read in the 5’→3’ direction, misreading the direction will alter meaning. Sixty-four … Read more
What is Geographical Indication? A Geographical Indication (GI) is basically a sign / mark used on products that come from a particular location and have qualities or reputation mainly due to that place. It’s considered as one of the forms of Intellectual Property Rights (IPR) which protects names or signs linked with geographic origin rather … Read more
What is Intellectual Property Right? Intellectual Property Right (often shortened as IPR) is described as a legal right that is given to protect creations of the mind, such as inventions, literary works, designs, and symbols used in commerce. Protection is granted so that creators are recognized and rewarded for their work, even when enforcement is … Read more
Habitat of Aspergillus clavatus Morphology of Aspergillus clavatus Cultural Characteristics of Aspergillus clavatus Culture media used for the growth of Aspergillus clavatus Life Cycle of Aspergillus clavatus Pathogenesis of Aspergillus clavatus Diseases caused by Aspergillus clavatus Treatment of Aspergillus clavatus diseases Prevention and control of Aspergillus clavatus FAQ
Kingdom: Fungi Division: Ascomycota Class: Eurotiomycetes Order: Eurotiales Family: Trichocomaceae Genus: Aspergillus Species: A. niger Aspergillus niger is considered one of the most common species of the genus Aspergillus, which has been widely distributed in soil, decaying vegetation, and indoor environments. It is usually recognized as a black mold, and colonies are often appeared dark brown … Read more