State the organelle being
described: Only found in plant cells, this is a layer made of cellulose that
surrounds the cell to provide structure and support.
This question is asking us to
identify the organelle or subcellular structure being described in the prompt. It must be exclusive to plant
cells, found on the outside of the cell, and it must provide structure and support
to the cell. In order to answer this question,
first we’ll draw and label a plant cell. Then we’ll identify the parts that
are only found in plant cells. And then we’ll be able to choose
Here’s a simplified diagram of a
plant cell. Let’s label what we see. The plant cell has a cell membrane,
which defines the boundary of the cell and controls what enters and what leaves. The plant cell contains cytoplasm,
a jellylike fluid that fills the internal space of the cell. The plant cell contains ribosomes,
tiny organelles that are the site of protein synthesis. We also see several mitochondria,
bean-shaped organelles that are the site of cellular respiration. The plant cell also contains a
nucleus, an organelle which stores and protects the genetic material or DNA.
In addition to the structures we
listed, the plant cell possesses a cell wall, a rigid outer layer that provides
structure and support. It possesses several chloroplasts,
organelles that give the plant its green color and are the site of
photosynthesis. The plant cell also possesses a
large central vacuole, an organelle that provides both storage and structure to the
plant cell. Well, we’ve labeled all the parts
of our cell.
Let’s recall that our question is
looking for an organelle that’s only found in plant cells. All of these organelles to the
right are found in both plants and animal cells, while the ones on the left are only
found in plant cells. So the correct response must be
cell wall, chloroplast, or central vacuole. Of these three, the layer that
surrounds the cell to provide structure and support is the cell wall.