Answer:
The fourth plant that receives pure water is the control group.
Explanation:
The election of a control group is essential in an experiment. Its principal purpose is to allow the discrimination of the results obtained by the treatment in the study, in this case, <em>the different concentrations of salty water that each plant receives</em>. The control group provides a reference point. It must be selected from the same population of the treatment groups. Both groups must be similar in every variable that might influence the results, <u>except for the study treatment.</u>
Answer:
An old penny rusting
Explanation:
A penny forming rust is the penny being chemically altered and changing form as opposed to dissolving sugar in water, which is still sugar, just mixed with water. It doesn't change the chemical makeup of the water or sugar.
Answer:
A you use apparent magnitude to find the absolute magnitude
Based on the CDC guidelines a person with a CD4+ cell count between 200-400 is regarded as being in <u>the second stage</u> of the HIV infection.
Acquired Immunodeficiency Syndrome
Acquired immunodeficiency syndrome (AIDS) is a condition caused by HIV (human immunodeficiency virus). AIDS is a chronic disorder and can become life-threatening for the infected person. The HIV viruses reproduce inside the host and while doing so they destroy the CD4+ immune cells which reduce the person's ability to fight against other diseases.
CD4+ cell count and AIDS
According to the CDC (U.S. Centers for Disease Control and Prevention), HIV infection is categorized into different stages based on the number of CD4+ cells.
- Stage 1: - CD4+ cell count is more than 500 per microlitre. There are no symptoms or AIDS-related conditions.
- Stage 2: - CD4+ cell count is more than 500 per microlitre. There are no symptoms or AIDS-related conditions.
- Stage 3: - The CD4+ cell count falls below 200 and AIDS-related symptoms and conditions are present.
Learn more about HIV infection here:
brainly.com/question/13662165
#SPJ4
The answer is A because it is not formed from decaying marine animals.
