Video Transcript
Which of the following tables
correctly differentiates between examples of structural and physiological support in
plants? (A) Examples of structural support
are cellulose in cell walls and lignin in xylem walls, and an example of
physiological support is the vacuole increasing or decreasing the turgidity of
cells. Or (B) an example of structural
support is the vacuole increasing or decreasing the turgidity of cells, and examples
of physiological support are cellulose in cell walls and lignin in xylem walls.
Plants have two kinds of support
that give them their structure and shape: physiological support and structural
support. Physiological support is provided
by the water in each plant cell’s vacuole, which exerts turgor pressure upon the
cell membrane, causing it to press against the cell wall, making the cells swollen
and firm and the plant as a whole rigid and upright. This support is temporary, meaning
that if the plant becomes dehydrated and the vacuoles lose water, the support
decreases, which can lead to the plant wilting.
Structural support describes the
permanent deposition of strong, rigid polymers into certain plant cell walls, which
persists even after the plant dies. An example of a structural support
polymer that is deposited into the cell walls of every plant cell is cellulose,
which makes the cells strong and prevents them from bursting when they’re filled
with water. Another example is lignin, which is
deposited into the cell walls of xylem vessels, making them strong, rigid, and
impermeable to water, thereby increasing the efficiency of water transport up
through the plant.
So, which of the tables is
correctly assigning examples of structural and physiological support? As we know, physiological support
is temporary and depends on the water content of the vacuoles in cells. So the vacuole increasing or
decreasing the turgidity of cells is an example of physiological support, suggesting
that the correct answer is option (A). As discussed, the deposition of
polymers like cellulose and lignin into cell walls provides structural support,
confirming that this is the correct table.
So, the table that correctly
differentiates between examples of structural and physiological support in plants is
(A). Examples of structural support are
cellulose in cell walls and lignin in xylem walls, and an example of physiological
support is the vacuole increasing or decreasing the turgidity of cells.
