Video Transcript
The picture provided shows an
organism belonging to the kingdom Plantae. What are the characteristics of
organisms belonging to this kingdom? (A) These organisms are eukaryotic,
multicellular, and heterotrophic. (B) These organisms are
prokaryotic, multicellular, and autotrophic. (C) These organisms are eukaryotic,
multicellular, and autotrophic. Or (D) these organisms are
prokaryotic, multicellular, and heterotrophic.
To answer this question, let’s
start by reviewing what the terms eukaryotic, heterotrophic, prokaryotic,
multicellular, and autotrophic mean. Organisms that are eukaryotic and
organisms that are prokaryotic differ considerably in their cellular structure. Eukaryotic cells contain
membrane-bound organelles including a membrane-bound nucleus, which prokaryotic
cells do not. While the DNA in eukaryotic cells
is packaged into multiple chromosomes found in this nucleus, in prokaryotic cells
it’s found in the form of circular chromosomes and several plasmids found loose in
the cytoplasm.
Most prokaryotic cells are
unicellular, meaning they’re made up of only one cell like a bacterium. Most eukaryotes however are
multicellular. This means that they’re made up of
multiple often differently specialized cells like we humans are. As plant cells like this one do
have a nucleus and other membrane-bound organelles like chloroplasts, we know that
they’re eukaryotic and multicellular. So we can exclude options (B) and
(D), as both of these say that they are prokaryotic.
Now we just need to work out
whether plants are heterotrophic or autotrophic. So let’s look at these terms
next. These two terms refer to how
organisms can obtain their food. Some autotrophs, like this plant,
can obtain their food by synthesizing it themselves through photosynthesis. They use water absorbed from the
soil and carbon dioxide absorbed from the atmosphere in the presence of light energy
usually from the sun to produce simple sugar molecules like glucose, which they can
then use to make more complex nutritious molecules. As autotrophic organisms only need
light in addition to these simple inorganic materials in order to produce their
food, they are often sessile, meaning they do not move around.
Heterotrophic organisms on the
other hand need to obtain their food from another living or once-living
organism. Heterotrophs must consume other
organisms in order to obtain their nutrition. They therefore need to be able to
move around the place to find or hunt other organisms to eat.
We know that plants can produce
their own food via photosynthesis, so they’re autotrophic. As we know that plants are not
heterotrophic, we can exclude option (A). So we’ve worked out that the key
characteristics of organisms belonging to kingdom Plantae are that these organisms
are eukaryotic, multicellular, and autotrophic.
