Answer: B
Explanation: Traits usually die off when they are unneeded by the organism, or if the trait causes harm to the organism's survival. Through natural selection, over time, the organisms with the best combination of traits for its survival will become the dominating species, and those with weaker traits may not survive long enough to pass off their traits to future offspring.
First, the yellow fever virus is phagocytosed by white blood cells. The phagocytosed white blood cell then travel through the lymph vessel. Since lymph node contain white blood and filter lymph, the yellow fever phagocytosed with white blood cell establish in the lymph node.
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>
Idk but you can ask google and I'm sure they will tell you