Final answer:
Prokaryotes fit more nucleotides into their smaller genomes due to lower genomic complexity and the process of supercoiling, which compacts DNA efficiently.Prokaryotes compact DNA with supercoiling; eukaryotes have linear, complex genomes.
Step-by-step explanation:
The reason why prokaryotes can fit more nucleotides in their smaller genomes is tied to their lower genomic complexity and more compact DNA packing strategies, such as supercoiling. Prokaryotic organisms, like Escherichia coli, have relatively small genomes (4.6 million base pairs) and utilize a single circular chromosome that is highly compacted through supercoiling. Proteins and enzymes like DNA gyrase play critical roles in maintaining this compact, supercoiled structure. By contrast, eukaryotic organisms have larger, more complex genomes that are stored linearly and involve multiple origins of replication and complex packing involving histones and nucleosomes.
The ability of prokaryotes, exemplified by organisms like Escherichia coli, to accommodate more nucleotides in their relatively compact genomes stems from their inherent genomic simplicity and efficient DNA packing mechanisms. Prokaryotic genomes, typically smaller, around 4.6 million base pairs, feature a single circular chromosome subject to high levels of supercoiling. DNA gyrase and other enzymes play crucial roles in maintaining this tightly coiled structure. In contrast, eukaryotic organisms exhibit larger, more intricate genomes arranged linearly. The genomic complexity involves multiple origins of replication and intricate packing mechanisms with histones and nucleosomes. The contrast in genomic organization highlights the prokaryotic advantage in nucleotide storage through streamlined, supercoiled DNA structures.