How many germ layers does a didermic organism have?

Didermic organisms, also known as diploblastic organisms, have two germ layers: the ectoderm and the endoderm. These layers arise during the early stages of embryonic development and give rise to different tissues and organs in the organism.

The ectoderm is the outer layer that typically develops into the skin and nervous system, while the endoderm is the inner layer that forms the lining of the digestive tract and associated organs. Some examples of didermic organisms include cnidarians like jellyfish and corals, which illustrate how these two germ layers can lead to the development of functional body plans.

Organisms with one germ layer are not classified as didermic, as they involve only the ectoderm without a distinct endoderm. Similarly, organisms that have three germ layers (ectoderm, mesoderm, and endoderm) are classified as triploblastic, which is a different developmental stage and complexity level. Four germ layers is not a recognized classification in this context, as biological development typically categorizes organisms into either one, two, or three layers.