Explain the tree types of animals body plan
Answers
Answer:
Animals can be classified by three types of body plan symmetry: radial symmetry, bilateral symmetry, and asymmetry.
Answer:
Animals can be classified by three types of body plan symmetry: radial symmetry, bilateral symmetry, and asymmetry.
Explanation:
Asymmetry is seen in two modern clades, the Parazoa (Figure 1) and Placozoa – although we should note that the ancestral fossils of the Parazoa apparently exhibited bilateral symmetry.
Radial symmetry is the arrangement of body parts around a central axis, as is seen in a bicycle wheel or pie. It results in animals having top and bottom surfaces but no left and right sides, nor front or back. If a radially symmetrical animal is divided in any direction along the oral/aboral axis (the side with a mouth is “oral side,” and the side without a mouth is the “aboral side”), the two halves will be mirror images. This form of symmetry marks the body plans of many animals in the phyla Cnidaria, including jellyfish and adult sea anemones (Figure 2). Radial symmetry equips these sea creatures (which may be sedentary or only capable of slow movement or floating) to experience the environment equally from all directions.