Video Transcript
Which of the following best
explains the theory of water movement by imbibition? (A) Imbibition is the force that
pushes water into the roots and vertically up the xylem. (B) Imbibition is the absorption of
water by dry materials, which occurs in plant cell walls. (C) Imbibition is the movement of
water from an area of low solute concentration to an area of high solute
concentration. Or (D) imbibition is the movement
of ions from the soil into the root hair cell and up the xylem.
Let’s start by defining the term
“imbibition.” The word “imbibition” comes from
the Latin word “imbibe,” meaning to drink. Imbibition describes the process of
water absorption by the cell walls of a plant. This process can be observed during
seed germination. When conditions are favorable, the
seed’s cells start to absorb water. As more and more water enters, the
seed becomes swollen in its appearance. So imbibition is important for seed
germination as it helps the seeds increase in size to sprout.
Now that we understand what is
meant by the term “imbibition,” let’s discuss the answer options to find the correct
one.
The first option suggests that
imbibition is the force that pushes water into the roots and vertically up the
xylem. This process is called root
pressure. This force describes the upward
pressure that develops in the roots by the push of water molecules into the roots
through osmosis. So option (A) is incorrect.
Option (B) might be the correct
answer as it states that imbibition is the absorption of water by dry materials,
which occurs in plant cell walls. This description correlates with
the description we mentioned earlier. But let’s have a look at options
(C) and (D) to be sure.
The movement of water from an area
of low solute concentration to an area of high solute concentration is called
osmosis. So option (C) is not the correct
answer.
Option (D) is also incorrect
because the movement of ions from the soil into the root hair cell and up the xylem
is called active transport. More precisely, active transport is
the movement of ions from a low concentration to a higher concentration. Note that in plants, the ion
concentration in the root hair cells is typically higher than in the dilute
solutions in the soil.
As mentioned previously, by looking
at the description of imbibition, it states that it is the absorption of water by
the cell walls. So option (B) is indeed
correct. Imbibition is the absorption of
water by dry materials, which occurs in plant cell walls.
