Answer: c
It says the answer needs to be 20 characters long)
The correct answer is - A) arthropods evolved before vertebrates did.
The arthropods have evolved much earlier than the vertebrates. They were on the scene millions of years before the earliest marine forms of the vertebrates. Because the arthropods were on the scene much earlier, they managed to use the newly formed suitable environment on the land. They were initially marine, but with only slight adaptations they were able to adapt to the terrestrial life.
Once the arthropods got out of the marine environment and started to take up the niches in the terrestrial environment, they experienced a real explosion in their evolution and diversification. They were the dominant land dwellers, and because of the lack of competition, as well as the higher levels of oxygen, they managed to reach pretty big sizes for their standards. Unfortunately for them, their brain capacity is limited to a very low level, so once the competition came on the scene, they were quickly pushed from the throne as the dominant terrestrial creatures.
I filled out a few boxes for you to start you off. I also gave you a direct research sources for some animals that will take you to the necessary information.
This is what I have so far as examples for you. Again, I said I wouldn't do all of your work for you, however, I will help you through your research and graph.
In interphase the dna is the form of loose threads called chromatin
