Video Transcript
Sclerenchyma tissues have a role
only in physiological support. Is this statement correct? Why? (A) The statement is incorrect
because sclerenchyma tissues are mainly involved in structural support. (B) The statement is correct
because sclerenchyma tissues have only a main role in the development and growth of
plants. (C) The statement is correct
because sclerenchyma tissues are mainly involved in reproduction in plants. Or (D) the statement is incorrect
because sclerenchyma tissues do not have any role in plant support.
Generally, we can distinguish
between two types of support in plants: structural support and physiological
support. Physiological support is temporary,
and it depends on maintaining a high volume of water in plant cells to keep their
shape. The main structures involved in
physiological support are the vacuole, which stores this water, and the cell
wall. When there is little water
available, water moves out of the vacuole and the cell, which means that
physiological support is not given and on a larger scale causes the plant to
wilt. However, when there is a sufficient
amount of water, the vacuole takes up this water and the cell wall prevents the
plant cells from bursting, making them rigid and swollen and on a larger scale
causing the plant to stand upright.
Structural support, in contrast, is
permanent and involves the deposition of strong polymers into certain cell walls in
specific parts of the plant. This maintains the shape of those
cells and of the plant as a whole.
There are three types of simple
tissue in a plant: parenchyma, collenchyma, and sclerenchyma. The cell walls of cells in
sclerenchyma tissue are thick and reinforced with a polymer called lignin and extra
cellulose. Sclerenchyma cells are generally
found in nongrowing parts of the plant to add structural support to them. For example, sclerenchyma cells can
be found supporting the vascular bundles in a stem, which are the plant tissues
responsible for transport.
The statement in the question
suggests that sclerenchyma tissues have a role only in physiological support. With our acquired knowledge, we
know that this is incorrect as sclerenchyma tissue is involved in structural
support, not physiological support. Looking at the answer options, we
can therefore immediately exclude answer options (B) and (C) as they both state that
the statement is correct, which is inaccurate. As we know that sclerenchyma
tissues are involved in structural support, we can also eliminate option (D), which
suggests that sclerenchyma tissues do not have any role in plant support.
This means that the correct answer
is option (A). The statement is incorrect because
sclerenchyma tissues are mainly involved in structural support.
