What do you call the body cavity that is lined by mesoderm?
Show answer & explanation
Correct answer: C
Explanation
The Correct Answer is Option 3 i.e. Coelom.
A coelom is a fluid-filled body cavity that is completely lined by mesoderm, the middle layer of embryonic tissue in triploblastic animals. This cavity provides space for the development and suspension of internal organs such as the heart, lungs, and digestive tract. It also allows for greater flexibility and complexity in body structure and function. Animals with a true coelom are called coelomates (e.g., annelids, mollusks, arthropods, chordates). The presence of a coelom is a key evolutionary advancement that supports the organization and protection of internal organs, efficient circulation, and locomotion.
Other Options:
-
Triploblasts: Animals with three germ layers (ectoderm, mesoderm, endoderm), but not all have a coelom.
-
Diploblasts: Animals with only two germ layers (ectoderm and endoderm); they do not develop a coelom.
-
Radial symmetry: A type of body symmetry (e.g., in jellyfish) where body parts are arranged around a central axis — unrelated to coelom.