Question

Sycon belongs to a group of animals which are best described as

• A. Unicellular or acellular
• B. Multicellular without any tissue organisation
• C. Multicellular with a gastrovascular system
• D. Multicellular having tissue organisation, but no body cavity

Answer 1

The correct option is B Multicellular without any tissue organisation

•Sycon is a sponge. Sponges belong to phylum Porifera. Sponges are the most primitive of multicellular animals. These animals exhibit only the cellular levels of body organisation and thus, are considered as the simplest forms among the metazoans. The restriction to the cellular levels of body organisation means that functions are carried out by individual cells or aggregate of cells.

• Sponges do not have a digestive system and respiratory system. The functions associated with these organs are performed by canal system.

• All sponges have a central body cavity called spongocoel which is lined by choanocytes or collar cells.

Hence, statement B is correct.

So, the correct answer is 'Multicellular without any tissue organisation'