Video Transcript
The image provided shows a group of
plant cells, each containing many chloroplasts and surrounded by a cell wall. Which of the following is not a
function of a plant cell wall? (A) To provide mechanical strength
to the cell, ensuring it does not burst under osmotic pressure. (B) To maintain the shape and
structure of the cell. (C) To allow water to pass through
and into the rest of the plant. (D) To receive signals and
communication from other cells by the use of receptors.
Let’s remove the image so we have
more space to work out which is the correct answer. This question asks us about the
role of the cell wall in plants. Plant cells differ from animal
cells because they contain a cell wall composed of cellulose that surrounds the
plasma membrane. The cell wall serves many
functions. Some of these functions include
providing strength, support, shape, and protection for the cell. Take note that even though the cell
wall forms the outermost layer of the plant cell, plant cell receptors are membrane
bound and located within the plasma membrane.
The cell wall is absolutely
necessary for facilitating the upright growth of plants. It does not only provide the
structural support for this to occur, but it also prevents the cell from bursting
when it absorbs too much water. A plant is able to take up water
and store it in an organelle called a vacuole. When a plant is well watered, it
should stand up straight and tall. But when a plant does not have
sufficient water, it will sag. This is because the vacuoles in the
plant cells are not adequately filled. However, when the plant has
sufficient amounts of water, the vacuoles will swell and push against the cell
wall. This is called osmotic
pressure. The cell wall ultimately prevents
the cell from bursting, and it also allows water to pass through to enter the plant
itself.
Now that we’ve discussed the role
of the cell wall in plants, we can go through the answer options to find the answer
which does not describe a function of the cell wall. We have learned that the cell wall
provides mechanical strength to the cell, ensuring it does not burst under osmotic
pressure. We have also learned that it
maintains the shape and structure of the cell. In order for the plant cells to be
able to take up water, the cell wall has to allow water to pass through and into the
rest of the plant. The correct answer to “Which of the
following is not a function of a plant cell wall?” is (D): to receive signals and
communication from other cells by the use of receptors.
