What can cause a gap in the rock record a) lack of rock deposition. b) erosion. c) neither erosion nor lack of deposition. d) both erosion and lack of rock deposition

You are given an electron micrograph of a bacterial cell. in the micrograph you can clearly see three thin layers of different densities surrounding the cell. based on the micrograph, you can infer that this cell is and would appear after application of the gram stain procedure. gram-negative / pink gram-positive / purple gram-positive / pink gram-negative / purple