microbiologists use the gram stain to aid in the identification of bacteria. what is the major difference between gram-positive and gram-negative bacteria? TRENDING
to establish a link between a specific bacterium and a skin disease, researchers have shown that the bacterium was present in sick persons but not in healthy individuals. they isolated the bacterium in a pure culture and demonstrated that experimental healthy animals injected with this culture became sick. what other experiment do researchers need to perform to be absolutely sure that the bacterium is responsible for the disease? TRENDING
a 45-n brick is suspended by a light string from a 2.0-kg pulley. the brick is released from rest and falls to the floor below as the pulley rotates through 5.0 rad. the pulley may be considered a solid disk of radius 1.5 m. what is the angular speed of the pulley? TRENDING