The second largest crater in the world was formed by the impact of a comet according to a 2014 study by researchers in Canada and Ireland. Colliding with Earth almost 1.85 billion years ago, the estimated diameter of the crater is 81 miles (130 km).
How big is a bacteria compared to a human cell? The size of a typical bacterial cell is 0.5-5.0 micrometers, a average human cell is 10 micrometers.8 people found this useful.Edit.he consensus among biologists is that only 5 to 10% of the trillions of cells in our bodies are human. The rest are alien cells: yeast, fungi, bacteria, viruses.
While all bacterial cell walls (with a few exceptions e.g. extracellular parasites such as Mycoplasma) contain peptidoglycan, not all cell walls have the same overall structures. Since the cell wall is required for bacterial survival, but is absent in some eukaryotes, several antibiotics (notably the penicillins and cephalosporins) stop bacterial infections by interfering with cell wall synthesis, while having no effects on human cells which have no cell wall only a cell membrane. There are two main types of bacterial cell walls, those of gram-positive bacteria and those of gram-negative bacteria, which are differentiated by their Gram staining characteristics. For both these types of bacteria, particles of approximately 2 nm can pass through the peptidoglycan.