Every animal has a distinct body plan, adapted in response to environmental pressures, that limits its size and shape.
Animal body plans can have varying degrees of symmetry and can be described as asymmetrical, bilateral, or radial.
Animal shape and body size are influenced by environmental factors as well as the presence of an exoskeleton or an endoskeleton.
Less efficient diffusion in larger cells led to multicellular organisms with specialized tissues that supply nutrients and remove waste.
An animal's body size, activity level, and environment impacts the ways it uses and obtains energy.
Vertebrates can be divided along different planes in order to reference the locations of defined cavities.