12. Why is it important to use a staining element in viewing especially colorless specimen? A. To protect the specimen. B. To keep the specimen flat. C. To see clearly the specimen. D. To bring out the starch in the specimen. 13. When viewing a sample of cheek cells using a microscope, the student placed the cells on a slide and placed a coverslip over it. What is the purpose of the coverslip? A. To keep the cells flat. B. To protect the cheek cells. C. To get a better view of the cells. D. To let the cheek cells, stay on the slide and not fall of it. 14. Dan prepared a thin sheet of onion skin and study using the microscope but he cannot view clearly the specimen. Should Dan adjust the coarse adjustment knob first then followed by the fine adjustment knob? A. No, because the draw tube and the body tube should be adjusted for clearer view. B. No, because fine adjustment knob must be adjusted first then the coarse adjustment knob. C. Yes, because the coarse adjustment knob is for the tilting of the microscope and fine adjustment knob is for the rotation of the revolving nosepieces and its lenses. D. Yes, because coarse adjustment knob is for the fast movement of the body tube and fine adjustment knob is for the slow movement of the body tube. 15. Lily examine a specimen but there was no image being viewed because the field of view is dark. Should Lily adjust the objective lenses? A. Yes, Lily should adjust the objective lenses because it is responsible in providing light. B. Yes, Lily should adjust the objective lenses because she can choose between low power and high power. C. No, Lily should adjust the diaphragm and the mirror because these parts are responsible in providing of light. D. No, Lily should adjust the fine adjustment knob and coarse adjustment knob because these parts are for giving light.​