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.
The vast majority of bacteria do not cause disease, and many bacteria are actually helpful and even necessary for good health. These bacteria are sometimes referred to as âgood bacteriaâ or âhealthy bacteria.â. Harmful bacteria that cause bacterial infections and disease are called pathogenic bacteria.taphylococcus aureus causes a variety of infections in the body, including boils, cellulitis, abscesses, wound infections, toxic shock syndrome, pneumonia, and food poisoning. Streptococcal bacteria cause a variety of infections in the body, including pneumonia, meningitis, ear infections, and strep throat.