species population community ecosystem biome and biosphere. since you are asking specifically about the levels of organization in an ecosystem er leave out the levels of biome and biosphere since they are both more complex than ecosystem
Answer:
Connective tissues support the tissues of the mucosa and connect it to the muscularis layer. The blood supply of the submucosa provides nutrients to the wall of the stomach. Nervous tissue in the submucosa monitors the contents of the stomach and controls smooth muscle contraction and secretion of digestive substances.
The stomach secretes acid and enzymes that digest food. Ridges of muscle tissue called rugae line the stomach. The stomach muscles contract periodically, churning food to enhance digestion. The pyloric sphincter is a muscular valve that opens to allow food to pass from the stomach to the small intestine.
A gene pool consists of all the genes within a chromosome . -Hope this helps :)
