Agnatha, the earliest vertebrates, are considered more primitive compared to Gnathostomata, which evolved later. Agnatha species are mostly scavengers or parasites, such as lampreys, which latch onto other fish to feed. Gnathostomata, with their jaws, dominate aquatic and terrestrial ecosystems. This group includes predators like sharks, and herbivores like grazing fish. Additionally, Gnathostomata possess more advanced skeletal systems, often with bones or cartilage providing robust support. Based on this evolutionary context, which of the following features is exclusive to Gnathostomata but absent in Agnatha?

Which of the following is not part of the subphylum Chelicerata?

What does the term “metamerism” refer to?

Mycobacterium ulcerans is an infectious bacterium of many clades. Since the ulcerans DNA was detected across multiple clades, this could mean…

Which of the following is not a characteristic of arthropods?

What class do sea stars belong?

The shoulder blade would be considered what with regards to the chest?

Below is a cladogram, use the information in the diagram to the answer the question. Which traits are shared by rodents and primates but not by rodents and birds?

What structure of on a female nematode serves as the opening to the reproductive tract, allowing for the passage of eggs and facilitating mating?

To what class does the sea cucumber belong?