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.
Harmful bacteria that cause bacterial infections and disease are called pathogenic bacteria. Bacterial diseases occur when pathogenic bacteria get into the body and begin to reproduce and crowd out healthy bacteria, or to grow in tissues that are normally sterile.treptococcal bacteria cause a variety of infections in the body, including pneumonia, meningitis, ear infections, and strep throat. Bacterial diseases are contagious and can result in many serious or life-threatening complications, such as blood poisoning (bacteremia), kidney failure, and toxic shock syndrome.