Long, streamlined bodies reduce friction and allow access to small spaces. This body type is found among amphisbaenians, nematodes, and caecilians. Body shape in each of these organisms would be considered a (n):

homologous character

parsimonious character

phylogenetic character

analogous character

analogous character

Explanation:

Amphisbaenians (reptiles), nematodes, and caecilians (amphibians) are a distinct group of organisms. The organisms of these groups found in a similar habitat have developed some similar features to become adapted to the surroundings. The presence of similar structures or features in the organisms of distinct groups occurs by convergent evolution. These structures are called analogous structures. They serve the same function but do not share basic structural homology. Therefore, body shape in these organisms is an analogous feature.

The analogous characters

Explanation:

In the given question, the body of the organism belonging to different phylum of animal kingdom shows the same structure and function although they are unrelated.

The streamlined body of the nematodes, the amphibians and the reptiles are similar in appearance and performs the same function. This trait has been the result of the natural selection as the same natural force has been applied to these three organisms which have resulted in acquiring the same type of adaptations in response to the same habitat.

The evolutionary biologists consider such organs as the analogous organs which are evolved through the convergent evolution.

Thus, the analogous character is the correct answer.