Question

How are animals grouped into phyla ?

Answer 1

Animals are grouped into phyla based on their:

1. Level of body organization- Various levels of body organization are atoms, molecules, cells, tissues, organs, organ systems, and organism.
2. Symmetry- Four types of symmetry are found in animals that are spherical, radial, biradial, bilateral
3. Body cavity- True coelom, pseudocoel, and haemocoel.
4. Notochord- It is a primitive beginning to the backbone. Notochords are only found in chordates (a group of animals that include humans). It appears as a flexible rod in the embryo and is made from cells of mesoderm, which is one of the 3 layers of cells of the embryo.