Movement of food along the digestive tract involving the contraction and relaxation of muscles is achieved by a process called

Achieved by a process called peristalsis

All cells come from preexisting cells. a cell divides its DNA in a process known as mitosis and its cytoplasmic contents in a process known as cytokinesis, producing two new daughter cells. The cell division enables tissues to form, grow and repair.

While all life begins as a single cell, the human body is not just one cell type. cells that can divide without becoming a specific cell type (i.e. skin cells) are known as stem cells or totipotent cells. These stem cells can become any type of cell.

When stem cells undergo mitosis and divide, they produce two cells. one cell remains a stem cell and the other is a partially specialized cell known as a progenitor cell. The progenitor cells become more and more specialized and eventually form specialized cells.

 Cells undergo a process of specialization or determination called differentiation to become neurons, muscle cells, or skin cells. stem cells are the source of all different cell types. Since all cells have the same DNA, epigenetic changes and the involvement of transcript factors are necessary to differentiate a stem cell into a specialized cell.