Answer:
Nuclear energy because it can never be reused again
The main difference between a plant cell and the animal cell is the presence of cell wall.
In the plant cell, the cell wall is present, but in the animal cell, the cell wall is absent.
Hence, in the onion cells, the cell wall around the cell would be clearly visible, whereas in the case of cheek cell, the cell would only be lined by a cell membrane, a cell wall would not be present.
Further, the plant cell would have the chloroplast, as they perform photosynthesis, but the animal cell would not have chloroplast. Unlike animal cell, the central vacuole in the plant cell is bigger and clearly visible.
Answer:
It is difficult to obtain a final conclusion with this information, but it is possible that the sample doesn't contain living organisms whose genetic material is composed of DNA. Another possible reason for this result is that the DNA extraction protocol used in the experiment is not suitable for this sample.
Hospolipid bilayer, with some protein, is what makes the cell membrane selectively permeable.
