What is a limitation of using electron microscopes to view specimens? A. You cannot view transparent specimens because of the microscope’s low resolution.
B. Electron beams are dangerous and can only be used sparingly.
C. You cannot view live specimens because the necessary preparation kills cells.
D. Resolution is weak and cannot make out details of very small specimens.

Which of the following is one of the four conditions necessary for natural selection to occur in a population? fewer organisms are born than the habitat can support mutation does not occur organisms have identical characteristics variation is inherited

Which of the following is likely not involved in this example of ecological succession? a) the rotting remains of plants add to the fertility of the soil. b)the soil becomes so fertile that eel grass is replaced by other plant species. c) the roots from plants stabilize the sediment, keeping it in place. d) the concentration of salt becomes so high that all plant life is destroyed.

Hairs that clean dirt out of the air in your nasal passages are called: a. sinus b. trachea c. cilia d. mucus