Late Secondary, University level; General Interest
60 minutes, Produced in Australia (2003)
Featuring living diatom cells photographed in the laboratory of Professor Jeremy Pickett-Heaps (FAA, FRS) at The University of Melbourne. This video introduces students to the ecological significance of these prolific and adaptable cells. It then embarks on a comprehensive exploration of all their varied activities which are carried out while the cells are enclosed within walls made of pure silica, one of the hardest and most refractory of minerals. Of particular interest are their strategies to circumvent the limitations that use of this material would otherwise impose on them - for example, how they render the wall porous, how the cells grow while enclosed within rigid walls and how they manage sexual reproduction.
They are superb objects for microscopical study and their extraordinarily beautiful cell walls have fascinated microscopists for over a hundred years. But living cells also offer equally spectacular images of cellular components such as golgi bodies, chloroplasts, mitochondria and nuclei, and activities such as streaming, cellular movement, mitosis and morphogenesis. Included in the video are numerous scanning electron micrographs and images from the confocal microscope that complement the images of living cells. Some of the activities such as rotation of the cytoplast during wall secretion, recovery from plasmolysis, attachment of cells to a substrate and secretion of chitin have never before been recorded live.
TOPICS and KEYWORDS:
cell membrane, cytoplasm, mitochondria, chloroplast, golgi body, vacuole, turgor pressure, nucleus, nucleolus, cytoskeleton, actin, microtubule, mitosis, cell division, morphogenesis, silica.