The range of the radar horizon dependson the height of the antenna and on the amount of bending of the radar wave.The bending is caused by diffraction and refraction. Diffraction is a propertyof the electromagnetic wave itself. Refraction is due to the prevailingatmospheric conditions.
Anaerobic bacteria, or anaerobes, are bacteria that do not need oxygen to live. In humans, these bacteria generally live in the gastrointestinal tract, but they may also be found in other places outside the body, including in the soil and water, in foods, and in animals.
Heterotrophic bacteria cannot synthesize their own food so they need organic material such as fish waste, dead bacteria, fish and plant matter, etc., and while some are aerobic, many are facultative anaerobes, meaning that they can survive in either the presence or absence of free oxygen.