Video Transcript
Organisms belonging to the kingdom
Plantae are eukaryotic. Which of the following best
explains what this means? (A) Their cells contain the
majority of their genetic material in a single circular chromosome. (B) Their cells contain the
majority of their genetic material in plasmids. (C) Their cells contain the
majority of their genetic material in the cytoplasm. Or (D) their cells contain the
majority of their genetic material in a membrane-bound nucleus.
In this question, we are being
asked about eukaryotic organisms. So, to answer this question
correctly, let’s review the key points about eukaryotes.
There is an incredibly diverse
range of living organisms on Earth. To make it easier to study these
organisms, they can be classified into kingdoms, a process known as taxonomy, from
the Greek word “taxis,” meaning order.
In 1969, a scientist called
Whittaker proposed a classification system made up of five kingdoms, which he called
Monera, Protista, Fungi, Plantae, and Animalia. All organisms in the kingdom Monera
are prokaryotes. The organisms in the other four
kingdoms are eukaryotes. So what is the difference between
prokaryotes and eukaryotes?
Let’s start with prokaryotic
organisms, which are all single-celled organisms. If we break down the name, we can
see that pro- means before and “kary” means kernel or nucleus. So “prokaryotic” means before a
nucleus. A prokaryote does not have any
membrane-bound organelles, which means they have no nucleus. You may then wonder where the
genetic material is found. Well, it is mainly found in a
single circular chromosome. There are also much smaller circles
of genetic material called plasmids.
Eukaryotes, on the other hand, are
made up of cells containing membrane-bound organelles. This includes the membrane-bound
nucleus, in which the majority of the organism’s genetic material is stored. If we again split up the name, the
prefix eu- means true. So “eukaryote” means true
nucleus.
We can now return to the
question. We have seen that prokaryotes store
their genetic material as a single circular chromosome and small plasmids. So we can rule out options (A) and
(B). We also learnt that all organisms
belonging to the kingdom Plantae are eukaryotes, the name meaning true nucleus. This means we know that the correct
answer to the question is (D). Eukaryotic cells contain the
majority of their genetic material in a membrane-bound nucleus.
