There are many ways of classifying bacteria. One method is based on the cell membrane. In 1884, a bacteriologist named Christian Gram created a test that could determine if a bacterium had a thick, ...

Gram-positive bacteria have thick cell walls. A Gram stain test, which involves a chemical dye, stains the bacterium’s cell wall purple. On the other hand, gram-negative bacteria stain pink instead.

There are two main types of bacteria, and these categories reflect the microbes' biology and their vulnerability to different antibiotics. When you purchase through links on our site, we may earn an ...

Negative thinking considers the weaknesses of human nature, the disadvantages of change, and how things can go wrong. Positive thinking considers the goodness of people, the advantages of change, and ...

When I started researching the science of happiness a decade ago, I was convinced negative emotions had no place in it. I thought that happiness meant you didn't have any negative emotions in your ...