DURATION: 20 mins.
An inspiring and challenging 20 minute video for high school students
This video starts by emphasizing the central importance of cells in life, and that living cells can only arise from other living cells by cell division.
After distinguishing mitosis (nuclear division) from cytokinesis (cell division), several animal cells are shown undergoing mitosis and a 3D animation shows how the mitotic spindle is assembled.
Chromosomes are shown attaching to spindle fibers both in living cells and in a 3D animation. All phases of mitosis are shown and discussed in detail.
Cell division in higher plant cells is similarly illustrated, emphasizing the role of the phragmoplast in cell-plate (cross wall) formation. Separation of homologous chromatids and single chromatids is shown in living spermatocytes undergoing meiosis I and II respectively.
The relationship between cell division and morphogenesis is introduced by showing several single-celled organisms that differentiate into complex shapes after every division. Other types of cells remain together after division to form simple multicellular organisms.
These two abilities are required for embryogenesis. Two examples (in frogs and zebrafish) show how repeated cycles of cell division and differentiation transform the ball of cells created by these divisions into recognizable embryos.