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Duckweed and the Snail
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V.I. Vernadskiy and duckweeds
On the chemical elementary composition of duckweeds (Lemna) as a
species characteristic
duckweeds, which grow in Kiev region and Peterhof region, were studied. Fourteen elements were investigated: Н2О, C, N, H, O, K, Na, Ca, Mg, Mn, Fe, Cl, P, S, Si. ItIt was established that the chemical composition for the separate species of duckweeds differed little depending on the locality or terrain. Identifiable differences in chemical composition are specific to the different species of duckweeds. |
On the position of chloroplasts in ivy-leaf duckweed
Ivy-leaf duckweed can change the color of its fronds.
In indirect or scattered light chloroplasts are arranged along the walls
of the cells, on surface of which the light/world falls at a right angle,
i.e., in the cylindrical parenchyma cells of the leaf on the parallel surfacesto
the leaf surface, and therefore, the tissue of such cells seems dark green,
if we look on them from the side, whence light/world falls.
As soon as direct sunlight begins to have its effect, chloroplasts are
transferred to the walls of cells, in parallel to the direction of the
incident rays/beams. If these are parenchyma cells, then chloroplasts
are grouped on long side walls, while short and lying/horizontal the right
angle to incident light walls prove to be those deprived of chlorophyll
and without pigmentation.
One can see well this displacement especially well in ivy-leaf duckweed, whose simple tissues contain only two layers of short green cells. |
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