Which phylum is characterized by animals that have a segmented body? a. Cnidaria b. Platyhelminthes c. Arthropoda d. Mollusca

Verified step by step guidance

1. Identify the key characteristic mentioned in the question: a segmented body.
2. Recall that the phylum Arthropoda includes animals like insects, arachnids, and crustaceans, which are known for having segmented bodies.
3. Compare this characteristic with other options: Cnidaria includes jellyfish and corals, which do not have segmented bodies; Platyhelminthes includes flatworms, which are also not segmented; Mollusca includes snails and clams, which lack segmented bodies as well.
4. Conclude that the phylum characterized by animals with a segmented body is Arthropoda.
5. Select the correct answer: c. Arthropoda.

Key Concepts

Segmentation in Animals

Segmentation refers to the division of an animal's body into repetitive segments, which can enhance mobility and allow for specialization of body parts. This trait is particularly significant in certain phyla, as it contributes to the complexity and adaptability of the organism.

Phylum Arthropoda

Arthropoda is a diverse phylum that includes insects, arachnids, and crustaceans. Members of this phylum are characterized by their segmented bodies, exoskeletons made of chitin, and jointed appendages, making them the largest group of animals on Earth.

Comparison of Animal Phyla

Understanding the differences between various animal phyla, such as Cnidaria, Platyhelminthes, and Mollusca, is crucial. While Cnidaria (like jellyfish) and Platyhelminthes (like flatworms) lack segmentation, Mollusca (like snails and octopuses) have a more complex body structure but do not exhibit true segmentation like Arthropoda.