Two cell types in placozoans make up the endoderm tissue layer are - D) gland cells and cylinder cells.
The Placozoa a marine free-living multicellular basal form of organism. These are condisered as the simplest structure of all animals.
Thus, two cell types in placozoans make up the endoderm tissue layer are - D) gland cells and cylinder cells.
Learn more:
https://brainly.com/question/4580106