Answer: The upper gastrointestinal tracts organs consist Esophagus, stomach and duodenum.
Explanation:
Gastrointestinal tracts is a organ system found in human beings and other animals that deals with intake of food, digestion of food, adsorbing nutrients from the digested food and expelling or excreting the waste products and undigested food.
The gastrointestinal tracts is divided into two, the upper and lower gastrointestinal tracts. The upper gastrointestinal tracts organs consist of Esophagus, stomach and duodenum while the lower gastrointestinal tracts consist of the large and small intestine. The structures include anus, colon,rectum,caecum.
Oncogenes result from turning on, or activating proto oncogenes. Proto oncogenes are genes that code for positive cell cycle regulators, so proto oncogenes code for proteins that turn on cell division. Proto oncogenes are normal genes, but when they are mutated, they become oncogenes. Oncogenes are expressed too much, which makes them turn on cell division too much, which is cancer.
