Development of the Pancreas in an Embryo into a Dual

Multiple Choice

Development of the pancreas in an embryo into a dual gland that has both exocrine and endocrine functions begins when

A) insulin is produced and bathes stem cells.
B) a transcription factor stimulates progenitor cells to give rise to exocrine or endocrine cells.
C) a globin gene duplicates and gives rise to alpha and beta globin genes.
D) progenitor cells become stem cells.