12.These new neurons had developed from neural progenitor cells, a type of undifferentiated neuron akin to a stem cell, in a process scientists call neurogenesis.
13.There are three types of neuroblastomas, and they're categorized based on the size and shape of the tumor cells: undifferentiated, poorly differentiated, and differentiating neuroblastoma.
17.Like other embryos, turtle embryos are made of undifferentiated cells that become specific cell types, and then organs and tissues, through gene activity and communication between cells.
20.In frogs, gene activity showed that even when an embryo looks like an undifferentiated blob-- cells are already starting down the paths to their eventual identities.