The answer is a stem cell. there is the unspecialized cell that generates or capable of renewing themselves through cell generation. Stem cells are important for living organisms for many reasons. In the 3- to 5-day-old embryo, called a blastocyst<span>, the inner cells give rise to the entire body of the organism, including all of the many specialized cell types and organs such as the heart, lungs, skin, sperm, eggs and other tissues.</span>
Tilling agitates the topsoil and removes ‘unnecessary’ vegetation so the main crop can grow without competition. Tilling improves soil aeration and drainage for plants to grow well. Nonetheless, it can lead to other consequences such as soil erosion because it loosens the soil and makes it easy to be carried away by wind and water.