Question

Differentiated embryonic layers are called
I. ectoderm
II. endoderm
III. mesoderm
lV. mesoglea

• A. I,II and IV
• B. I, II and III
  
• C. II and IV
• D. All of the above

Answer 1

The correct option is B I, II and III


Differentiated embryonic layers are called ectoderm, mesoderm and endoderm. Mesoglea is the undifferentiated layer present in between the ectoderm and endoderm in sponges. Animals in which the cells are arranged in two embryonic layers, an external ectoderm and an internal endoderm, are called diploblastic animals, e.g. coelenterates. Those animals in which the developing embryo has a third germinal layer, mesoderm, in between the ectoderm and endoderm, are called triploblastic animals e.g. platyhelminthes.