Question

multiple select question
select all that apply
select the three embryonic germ layers present in all eumetazoans except jellyfishes and their relatives.
ectoderm
mesoderm
placoderm
blastoderm
endoderm

Explanation:

Eumetazoans (except jellyfishes and their relatives) have three embryonic germ layers. The ectoderm is the outermost layer, the mesoderm is the middle layer, and the endoderm is the innermost layer. Placoderm is a group of extinct armored fish, not an embryonic germ layer. Blastoderm is a layer of cells in animal embryos (not a germ layer in the context of this question).

Answer:

ectoderm, mesoderm, endoderm