In the experiment of plasma wall separation, if the torn onion epidermis is accompanied by a lot of mesophyll, the experimental effect is poor. The main reason is () A. mesophyll cells.
Single-layer structure can be observed under general microscope, and its thickness should not exceed 4 microns. When doing plasma wall separation experiment, if you tear off a lot of mesophyll, you will see a lot of overlapping images of cells under the microscope, which is generally the most important thing to avoid with a microscope, because it is not clear to see, resulting in poor experimental results.
So choose: C.