Question

While there's a general correspondence between a species' complexity, its number of genes, and its total genome size, there are many variation on and exceptions to this.

Answer 1

Genetic diversity relates to differences in genetic makeup within a species and between species, underlying evolutionary processes.

Step-by-step explanation:

While the complexity of a species often coincides with its number of genes and overall genome size, considerable variations and exceptions exist. Genetic diversity refers to the differences in genetic makeup both within a population and between populations, and it serves as the foundation for evolutionary change. For example, although the human genome contains approximately 3.4 billion base pairs, there is a wide range of genome sizes in other species. The genome size in eukaryotes can be from a mere 2.2 million base pairs in certain microorganisms to over a trillion in some amoebae, and this does not always correlate with the number of genes.

Plants and bacteria present notable examples of genome size variation, with plant genomes potentially reaching up to 150 billion base pairs and the existence of polyploidy (having multiple copies of chromosomes). Conversely, bacterial genomes are smaller. These disparities are also seen in viruses, with genome sizes ranging broadly. Surprisingly, there is no straightforward correlation between genome size and gene count. For instance, a multitude of non-coding DNA exists within larger genomes with no direct link to the number of functional genes.