Question: Compare the nuclear DNA content and cell volume of each species. Which species have the greatest volume and DNA content?
Step-by-step explanation:
We can see from the graph that nuclear DNA content is directly proportional to cell volume, and in fact this relationship is linear. In human polyploid cells (blue) there is also a linear relationship if linear regression is performed. This means that the higher the cellular DNA content, the higher the cell volume.
Now, notice that the yellow line always has more nuclear DNA content than the other lines. And that all the lines reach an approximately equal cell volume but they have different nuclear DNA content for each cell volume.
According to the graph, the yellow line represents the vertebrates. Since this line represents the line that has more nuclear DNA content than the other lines for a specific cell volume, we can conclude that the species that have the greatest volume and DNA content are the Vertebrates.
Answer: we can conclude that the correct answer is:
Vertebrates.