(20 13? The correct description of the biological experiment shown in Huizhou Simulation is () A. If (1) refers to observing the developing substance with a high magnification magnifying glass,

A, Figure ① Under high magnification, the purple onion epidermal cells are separated from the plasma wall. Because the depth of 0.3g/ml sucrose solution is greater than the depth of cell fluid, the cells lose water, which shows that the vacuole gradually becomes smaller and the color gradually darkens, and A is correct;

B, because what is observed in the microscope is inverted, and the mitotic cells are located on the left side of the field of vision, it is wrong to observe the onion root tip image in a field of vision with a low-power microscope. If you want to see the mitotic cells clearly, you should move the film to the left appropriately;

C, Figure ③ shows that the microscope lens is changed from A to B, the magnification increases, the number of cells observed in the field of vision decreases, and C is wrong;

D when investigating the population density of dicotyledonous plantain, the quadrat can only count the individuals on the adjacent sides. Therefore, the number of individuals in the quadrat is 10, and its population density is 2.5 plants /m2. D is correct.

So choose ad.