A selection of Mechanical calculators: The basic operating principles of mechanical calculators changed little from the end of the 19th century to their obsolescence in the 1970s, though there were many developments in the mechanisms and the materials used.
Post. Share. Bacteriophages are viruses that infect bacteria. A bacteriophage can have a protein tail attached to the capsid (protein coat that envelopes the genetic material), which is used to infect the host bacteria.Scientists have long sought to uncover the structure and function of viruses. bacteriophage can have a protein tail attached to the capsid (protein coat that envelopes the genetic material), which is used to infect the host bacteria.
Conversely, a number of diseases that impact humans are caused by bacteria. Bacteria that cause disease are called pathogenic bacteria, and they do so by producing poisonous substances called endotoxins and exotoxins.These substances are responsible for the symptoms that occur with bacteria related diseases.The symptoms may range from mild to serious, and some can be deadly.holera is an intestinal infection caused by the bacteria Vibrio cholerae. Cholera is a food-borne disease typically spread by food and water contaminated with Vibrio cholerae. Around the world, approximately 3 to 5 million cases per year with approximately 100,000 plus deaths occur.