Question

Which of the following phylum possesses organ level with beginning of primitive organ system and organ system level of body organisation respectively?

• A. 1, 2 and 3 are correct
• B. 1 and 2 are correct
• C. 2 and 4 are correct
• D. 1 and 3 are correct

Answer 1

The correct option is D 1 and 3 are correct

All multicellular organisms do not exhibit the same level of organisation. The levels of organization might be cellular, tissue level, organ level or organ system level. Sponges show a cellular level of organisation. Hydra and jellyfish show tissue level of organization. An organ grade level of body organisation starts from flatworms - this also shows beginning of primitive organ system. Organ system is seen in roundworms, earthworms, crabs and in all higher animals.

Protozoa belong to the kingdom Protista and are unicellular eukaryotic organisms.