An electron microscope (EM) was used to view a cell. The maximum dimension of the cell was observed at a magnification ×30 000. The image on the EM screen showed a maximum length of 30 mm. Which of the following mature healthy cells was being magnified?
one coccus bacterium in a Staphylococcus cluster
one lymphocyte from a human
one mature human red blood cell
one sensory neuron from a human
one palisade cell from a wheat plant