Final answer:
Future kidney cells and heart cells can differentiate into their respective specialized cell types because they express different sets of genes during development and utilize different transcription factors.
Step-by-step explanation:
Future kidney cells and heart cells can differentiate into their respective specialized cell types because they express different sets of genes during development and utilize different transcription factors. During differentiation, embryonic stem cells undergo changes in gene expression, leading to the development of specific cell types. The expression of different genes and the utilization of different transcription factors allow kidney cells and heart cells to acquire their unique structures and functions.