The pathogen that causes cholera is a prokaryote.

1. (a)(i)Fig. 5.1 shows an electron micrograph of the pathogen that causes cholera. [Figure 5.1] Name the type of electron microscope used to produce the image shown in Fig. 5.1.[1]
2. (a)(ii)Name the species of prokaryote that causes cholera.[1]
3. (b)The passage contains a description of the main features of prokaryotic cells. There is one factual error in the passage. Prokaryotic cells are unicellular and generally between 1µm and 5µm in diameter. Prokaryotes do not have organelles surrounded by double membranes. They do have cell surface membranes, 70S ribosomes and a cellulose cell wall. The DNA of a prokaryotic cell is circular and is found free in the cytoplasm rather than enclosed in a nuclear envelope. Identify and correct the factual error in the passage.[1]

This question uses a diagram from the original paper, which isn't shown here. Open the full paper from the past papers archive to see it.