What is the primary role of cutin
and suberin in plants? (A) To provide structure and
support to the vascular tissues. (B) To maintain the shape of the
reproductive organs. (C) To maintain the shape of cell
walls. (D) To act as impermeable and
waterproof barriers. Or (E) to determine what enters and
leaves the plant cells.
This question asks us about the
role of cutin and suberin, which are two different polymers that can be deposited
into plant cell walls. The permanent deposition of
polymers, such as cutin and suberin, into certain plant cell walls are examples of
structural support mechanisms in plants.
Cutin is a substance present in the
cell walls of epidermal cells, forming a layer called the waxy cuticle on the
surface of certain parts of the plant, like its leaves. Cutin does not only provide some
extra strength and rigidity to these cells but also, somewhat more importantly, acts
as an impermeable barrier to water. This is especially helpful in the
waxy cuticle, as it helps to prevent the entrance of pathogens into the plant’s
inner tissues, as water droplets and any waterborne pathogens within them are likely
to drop right off the leaves.
Suberin is a substance found in
corky plant tissue, which often forms in response to infection or after a leaf
drop. Like cutin, suberin also acts as an
impermeable and waterproof barrier, helping to reduce the risk of infection, albeit
in the case of suberin this is not in the waxy cuticle but at vulnerable newly
Therefore, we can deduce that the
correct answer to this question is (D). The primary roles of cutin and
suberin are to act as impermeable and waterproof barriers.