Following gastrulation, the next major development in the embryo is neurulation, which occurs during weeks three and four after fertilization. This is a process in which the embryo develops structures that will eventually become the nervous system
Ans: Most genes contain the information needed to make functional molecules called proteins. (A few genes produce regulatory molecules that help the cell assemble proteins.) The journey from gene to protein is complex and tightly controlled within each cell.
The ileum contains villi that project into the lumen and increase the amount of surface area.
Villi are small finger-like structures that project into the lumen of the small intestine. Villi increase the surface area of the intestinal walls for easy and quick absorption of digested food with the addition of digestive secretions. Villi vary in length from about 0.5 to 1 mm. They are usually found in large numbers at the beginning of the small intestine and they reduce toward the end of the tract.