Video Transcript
Fill in the blank. The genetic material of organisms
in the kingdom Monera is largely contained within a circular blank. (A) Chromosome, (B) nucleus, (C)
nucleosome, (D) gene.
This question asks us about where
most of the genetic material is stored in organisms belonging to the kingdom
Monera. Organisms in the kingdom Monera are
prokaryotic. Let’s review what we know about
prokaryotic organisms to determine the correct answer.
A defining feature of prokaryotes
is that they do not contain a nucleus to contain their DNA. Instead it floats freely in the
cytoplasm. Therefore, we can eliminate answer
choice (B). A nucleus is found in eukaryotic
organisms. In addition, we can eliminate
answer choice (C) as well, because nucleosomes are a characteristic of
eukaryotes. Eukaryotic cells have their DNA
exist mainly as linear chromosomes that are packaged tightly. This is accomplished by DNA winding
around special proteins called histones. This forms structures called
nucleosomes. These nucleosomes can then further
coil to form the chromosome. Histones and nucleosomes are not
found in prokaryotes.
We can also eliminate answer choice
(D). A gene is a section of genetic
material that codes for a functional unit, for example, a protein. There can be thousands of genes in
a single chromosome, which we can see here represented as these pink lines. These genes are linear and are not
circular. Also, genes are found in genetic
material and not the other way around. So if we were to fill in the blank
with this option, it would be incorrect.
Most of the genetic material in
prokaryotes is found in a single, circular chromosome. Additional DNA can also be found on
structures called plasmids. Therefore, in the statement “The
genetic material of organisms in the kingdom Monera is largely contained within a
circular blank,” the option that best fills in the blank is given by answer choice
(A), chromosome.
