Introduction Bacteriophages not only infect and kill cells but also sometimes transfer DNA from one cell to another. This process by which foreign DNA is introduced into a cell by a virus or viral vector is called transduction. Phages capable of transduction are called transducing phages. Donor strain is the original bacterial strain in which … Read more
Introduction They are small, circular, self-replicating and double-stranded DNA molecule present in bacterial cell in addition to bacterial chromosome. So, plasmids are genetic elements that replicate independently of the host chromosome. Unlike the viruses plasmids do not have an extracellular form and exist inside cells simply as free and typically circular DNA. Plasmids carry gene … Read more
Introduction It is a natural process, which has been derived from the Greek word ‘eutrophos’ that means well-nourished or enriched. This enrichment leads to other slow processes which is called as “natural aging of lakes”. C.H Weber described eutrophication as nutrient rich conditions that is used to determine the flora of German peat bogs as eutrophe, … Read more
Introduction of Natural Killer Cells Natural killer cells are class of lymphocytes that respond to intracellular microbes by killing the infected cells and by producing macrophage activating cytokines. They comprise about 10% of the lymphocytes in the blood and peripheral lymphoid organs. These cells contain abundant cytoplasmic granules and express characteristic markers but they do … Read more
Introduction to infection An infection is the detrimental colonization of a host organism by a foreign species. In an infection, the infecting organism seeks to utilize the host’s resources to multiply, usually at the expense of the host. The infecting organism, or pathogen, interferes with the normal functioning of the host and can lead to … Read more
S.N Active immunity Passive immunity 1. Produced actively by the immune system of the host. Received passively by the host and the host immune system does not participate. 2. Induced by infection or by contacts with immunogens. Conferred by introduction of ready-made antibodies. 3. Immune response is durable and effective. Immune response is short … Read more
Important terminologies Genes: Genes are small sections or segments of DNA, called cistrons within the genome that code for proteins. It determines particular character of an organism. It is a hereditary unit which is transmitted from one generation to another. Locus: It is a particular position or place where gene is located on a chromosome. … Read more
Group Virus Characteristics Clinical importance Retroviruses Human T-cell leukaemia virus(HTLV-1) Human immune deficiency virus (HIV) Spherical enveloped virus, 100nm in diameter Icosahedral cores contain two copies of linear RNA molecules and reverse transcriptase. Differs from other retroviruses … Read more
A condition in which the number of red blood cells, the normal concentration of hemoglobin, or the hematocrit is below normal is called anemia. It decreases the blood’s oxygen carrying capacity. Anemia is usually a symptom of underlying diseases. There is usually an abnormally high amount of bilirubin in the plasma when anemia is due … Read more
Biotechnology is the controlled use of biological agents such as microorganism or cellular components for beneficial use. It is comparatively a new discipline of science in which the latest technology has been applied to biological organisms for human welfare. The recent progress in biotechnology is due to understanding and application of principles of molecular biology, … Read more