Because the dark box is blending in with the shadows, however the white box is bright and easier to see
Elodea cells change when aquarium water was supplanted with a hypertonic arrangement is the point at which the cell layer isolated from the cell divider and moved towards the center of the cell. The cytoplasm and chloroplas±s moved towards the center of the cell. The cell shrank and progressed toward becoming plasmolyzed.
Cu, Te, N.... Good luck ::)
