Asymmetrical are organisms, such as sponges, that have no true symmetry.
Bi-lateral.
Organisms that are considered to be simple, such as corals, sponges, urchins, many bacteria and protists all lack bilateral symmetry. The symmetry of these animals is one of the ways they are distinguished from each other and classified into groups.
Asymmetry is the lack of symmetry.
Sponges are asymmetrical. Organisms in Cnidaria have radial symmetry while organisms in Arthropoda exhibit bilateral symmetry.
Asymmetry
Sponges
Of course,gastropods [eg:-snail] do not show any symmetry
wrybill, crossbills
Porifera and Cnidaria
Symmetry in biology is the balanced distribution of duplicate body parts or shapes. The body plans of most multicellular organisms exhibit some form of symmetry, either radial symmetry or bilateral symmetry or "spherical symmetry". A small minority exhibit no symmetry (are asymmetric).
Bodies of most sponges completely lack symmetry. These organisms are called asymmetrical. Some animals such as sea anemone have a radial symmetry where cutting through the center will produce equal parts. There are also those with a bilateral symmetry where dividing into half will produce roughly mirror image parts.
Prokaryotes are organisms whose cells lack nuclei. An example of a prokaryote is bacteria.
Prokaryotes