For the answer to the question above, I think that <span>the initial titer that has been done to her may have been done too early in the infection that detectable levels of antibody were not present yet so that's why they have to repeat it.</span>
Muscular: The muscular system helps the frog to move. This system can help them escape from predators and catch prey.
<span>Skeletal: The skeletal system provides support for the frogs body. This system goes along with the muscular system
the skeletal part is support for the muscular parts</span>
Yes, it is possible that evolution occurs in this case.
At first, the new insecticide is effective against the boll weevil. Spraying the insecticide will kill the boll weevil in a way. The insecticide might attack boll weevil enzyme or any part of its organs.<span>
But some of them might have a mutation that renders the insecticide ineffective. The mutation probably happens to DNA that code the enzyme or protein that targeted by the insecticide, makes the insecticide completely ineffective.
The next spray will kill all old organism, leaving the new resistant organism in less competition area. This will allow the resistant organism to grow fast and eventually replace all the old organism in the area.</span>