Video Transcript
The diagram provided is a drawing
of a eukaryotic cell. Which structure is indicated by
Y?
This question presents us with a
diagram of a eukaryotic cell. Eukaryotic cells contain a nucleus
and other membrane-bound organelles. We can see that our mystery
structure Y is located inside a larger circular structure that’s surrounded by
membranous folds. This larger structure is the
nucleus, and the membranous folds make up the rough endoplasmic reticulum, the
smooth endoplasmic reticulum, and the Golgi apparatus. To work out what Y is, let’s review
the structures of the nucleus.
The nucleus houses all of the
genetic information required for protein production and other life processes. Genetic information is stored in a
long molecule called DNA, which is coiled up into chromatin so that it can fit
inside the nucleus. As we can see, the chromatin is
represented as long thin strands and is therefore not our mystery structure. The nucleus is surrounded by the
nuclear envelope, which contains nuclear pores that allow small molecules like mRNA
to move in and out of it. The nuclear envelope is directly in
contact with the rough endoplasmic reticulum and is therefore also not structure
Y.
The final component of the nucleus
is a large dense structure called the nucleolus. The nucleolus is the site of
ribosome synthesis. You may recall that ribosomes are
the organelles that are responsible for synthesizing proteins. We have therefore solved the
mystery and deduced that structure Y is the nucleolus.
