Sponges represent one of the simplest animal body plants. Their bodies lack true tissues and organs. Which feature of sponge cells supports its classification under the animal kingdom?
(a) Absence of mitochondria
(b) Ability to photosynthesise
(c) Presence of a cell membrane
(d) Presence of a cell wall
(c) Presence of a cell membrane
Explanation: The animal cells, including the cells of sponges, have eukaryotic cellular organisation. The animal cells are surrounded by cell membrane and have cellular organelles such as mitochondria, ER, Golgi, etc. Unlike animal cells, the plant cells also possess cell wall and chloroplast. Therefore from the given options, presence of cell membrane can be used to classify sponge as animal. It should be noted, however, cell membrane is found in all the organisms.
