The embryos of all animals undergo gastrulation, a dramatic reorganization of cells critical to formation of the animal body.
do you understand all the terms associated with gastrulation? drag the terms to appropriate blanks to complete the sentences below:
gastrula, blastopore, archenteron.

a) gastrulation is a dramatic reorganization of the hollow blastula into a two-layered or three-layered embryo called a
b) invagination of cells into the blastocoel forms a tube called the
c) the open end of the archenteron is called the