A tracheotomy is performed if enough air is not getting to the lungs, if the person cannot breathe without help, or is having problems with mucus and other secretions getting into the windpipe because of difficulty swallowing. There are many reasons why air cannot get to the lungs.
Trending Now. Answers. Best Answer: Yes, the smallest unit of evolution is the population. The reason is, the techical definition of evolution is change in allele frequency. You have to have a population in order to run the statistics to measure if there has been a change. Remember, a population does not necessarily mean all animals of one species.
The number of steps an organism is from the start of the chain is a measure of its trophic level. Food chains start at trophic level 1 with primary producers such as plants, move to herbivores at level 2, predators at level 3 and typically finish with carnivores or apex predators at level 4 or 5.The path along the chain can form either a one-way flow or a food web.ood chains start at trophic level 1 with primary producers such as plants, move to herbivores at level 2, predators at level 3 and typically finish with carnivores or apex predators at level 4 or 5.