Question

How does the body plans of animals with bilateral and radial symmetry differ?

Answer 1

Hint: Body plans are a group of structural and developmental characteristics. These morphological features are used to classify groups of all true animals.

Complete answer:
By the means of body plans, all true animals can be divided into three groups based on the type of symmetry of their body plan- radially symmetrical, bilaterally symmetrical, and asymmetrical.

Asymmetrical animals are those with no pattern or symmetry. Examples of animals with asymmetrical body plans are- sponge and parazoa. Radial symmetry is the arrangement of body parts around a central axis. Only a few animal groups display radial symmetry. This type of body plan is found mostly in aquatic animals. This form of symmetry represents the body plans of animals in the phyla Ctenophora and Cnidaria, including jellyfish and adult sea anemones. Bilateral symmetry is the arrangement of body parts around a sagittal plane. This results in two mirror-images. This results in the right and left halves. This form of symmetry represents the body plans of Echinodermata, butterfly, crab and the human body.

Radial symmetry is in contrast to bilateral symmetry. Bilateral symmetry cut into equal halves through one radius, while radial symmetry animals cut into two equal halves through radii.
The bilateral symmetry animals body are divided into two equal halves from a particular radius passing through the centre. The direction of cutting is fixed. The radial symmetry animal's body is cut into two equal halves from all the radii of the animal's body passing through the centre.

Note: The key difference between radial and bilateral symmetry is that radial symmetry generates identical body halves around the central axis whereas bilateral symmetry generates only two sides as left and right.