Duke University Medical Center. "Appendix Isn't Useless At All: It's A Safe House For Good Bacteria." ScienceDaily. ScienceDaily, 8 October 2007.
de Lacerda Rodrigues Buzatti KC, da Silva RG, e Silva Rodrigues BD (2017) Incidental and Prophylactic Appendectomy in Clinical Practice: A Review Article J Surg Transplant Sci 5(3): 1060.
Immune system is a system of the body that protects it from all foreign substances from the outside (viruses, bacteria, fungi, etc.) and controls the destruction of failed or outdated cells (for example, it is immunity that protects us from tumour formations). In order for immune cells not to destroy the cells of their own body, there is immunological tolerance.
While plants do their best to scare away those who want to eat them by producing all sorts of complex poisons and toxins, ironically, some of them are now used by humans only because of those very poisons.
One of the co-founders of the United Fruit Company (now Chiquita) was Minor Cooper Keith. He built a railroad in Costa Rica and planted many banana trees along the way to feed the workers. When the government could no longer fund the project, Keith had to come up with something to pay back the huge loan he had received. He decided to start using the newly built railroad to export bananas to the United States.
A sloth can move slowly, but movement is not his primary defense method. Camouflage is a great way to go undetected. And this is where sloths have become experts over a long period of their evolution.
Low frequency sounds are better transmitted through bone than high frequency sounds. This is why people tend to feel the low bass notes in music more than the higher pitched notes. This is also why your own voice sounds different to you than it does to other people.