Detailed Instructions: In this task, we ask you to elaborate the sentence without changing its general meaning. You can do so by explaining further the input sentence, using more precise wording, adding qualifiers and auxiliary information etc.
Problem:iPS cells are like embryonic stem cells from a blastocyst ( the embryo a few days after fertilization ) .
Solution:
iPS cells closely resemble embryonic stem cells , the " in vitro " equivalent of the part of the blastocyst ( the embryo a few days after fertilization ) which grows to become the embryo proper .