Answer:
The effectiveness of chemical disinfectants has historically been compared to phenol.
Explanation:
The effectiveness of a disinfectant or antiseptic can be determined in a number of ways. Historically, a chemical agent’s effectiveness was often compared with that of phenol, the first chemical agent used by Joseph Lister. In 1903, British chemists Samuel Rideal (1863–1929) and J. T. Ainslie Walker (1868–1930) established a protocol to compare the effectiveness of a variety of chemicals with that of phenol, using as their test organisms Staphylococcus aureus (a gram-positive bacterium) and Salmonella enterica serovar Typhi (a gram-negative bacterium). They exposed the test bacteria to the antimicrobial chemical solutions diluted in water for 7.5 minutes. They then calculated a phenol coefficient for each chemical for each of the two bacteria tested. A phenol coefficient of 1.0 means that the chemical agent has about the same level of effectiveness as phenol. A chemical agent with a phenol coefficient of less than 1.0 is less effective than phenol. An example is formalin, with phenol coefficients of 0.3 (S. aureus) and 0.7 (S. enterica serovar Typhi). A chemical agent with a phenol coefficient greater than 1.0 is more effective than phenol, such as chloramine, with phenol coefficients of 133 and 100, respectively. Although the phenol coefficient was once a useful measure of effectiveness, it is no longer commonly used because the conditions and organisms used were arbitrarily chosen.
Biologists say that living things are organized as living things contain specialized and coordinated parts.All living organisms are made up of one or more cells, which are considered the fundamental units of life.The individual organisms can be organized into the following levels:
cells, tissues, organs, organ system and organisms.
Answer: Sea snakes have many adaptations. Like for instance, they have paddle-like tails to help swim more efficiently, and a special flap of tissue to prevent water from entering its lungs.
Explanation:
They develop these adaptations for survival purposes.
Answer:
True, fasting blood sugar levels are generally higher in the early morning due to the increase hormonal activity during the night, then tend to decrease to more normal levels during the day.
Explanation:
Internal organs and tissues of an organism