• Microbiology

    Morphology of Bacteria

    Size The unit of measurement used in bacteriology is the micron (micrometre) 1 micron (μ) or micrometre (μm) – one-thousandth of a millimetre 1 millimicron (mμ) or nanometer (nm) – one-thousandth of a micron or one-millionth of a millimetre 1 Angstrom unit (Å) – one-tenth of a nanometer The limit of resolution with the unaided eye is about 200 microns. Bacteria aresmaller which can be visualized only under magnification. Bacteria come in a great many sizes and several shapes. Most bacteria range from 0.2 to 2.0 μm in diameter and from 2 to 8 μm in length. (anoverall average size of 1 to 10 μm.) Shape Depending on their shape,…

  • Biology,  Botony,  MCQ


    1. Which one belongs to monera? (a) Amoeba (b) Escherichia (c) Gelidium (d) Spirogyra. Answer and Explanation: 1. (b): All prokaryotic organisms comes under Kingdom monera. Escherichia coli is a bacteria. Monera includes bacteria, mycoplasmas, cyanobacteria (blue green alga) and actinomycetes. 2. The main difference in Gram (+) ve and Gram (-) ve bacteria resides in their (a) cell wall (b) cell membrane (c) cytoplasm (d) flagella. Answer and Explanation: 2. (a): Danish bacteriologists Christian Gram for the first time classified bacteria on the basis of the cell wall into two groups – gram +ve and gram -ve by staining with crystal violet and safranin. Gram +ve cell walls are less complex…

  • Biology,  Zoology


    Includes the bacteria and cyanobacteria (commonly called blue-green algae). Since only bacteria are prokaryotic (lacking a true nucleus), that is without nuclear membrane), monera is the only prokaryotic kingdom. Bacteria were the first organisms to evolve on planet earth afterlife originated around 3.5 billion years ago and were the only organisms on earth for almost the next two billion years. All bacteria and cyanobacteria are single-celled or unicellular (monere : single) Monerans are also the most numerous of all living organisms. https://youtu.be/uYZXWL6V7OU Structure of a bacterial cell The single-celled bacterium has a cell wall made of compound peptidoglycancovering the cell membrane; a single chromosome. The cell has ribosomes but nomembrane-bound…


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