Final answer:
The transcription regulator that activates all muscle specific genes for skeletal muscle cell specification is MyoD, a member of a transcription factor family that promotes gene expression for muscle differentiation.
Step-by-step explanation:
The specific transcription regulator that can switch on all muscle specific genes required for the specification of skeletal muscle cells is known as MyoD. MyoD is part of a family of transcription factors that play a crucial role in muscle differentiation. These transcription factors bind to regulatory elements near promoters of muscle-specific genes, promoting transcription and ultimately the expression of muscle-specific proteins.
A transcription factor is a protein that regulates gene expression by binding to DNA and influencing whether a gene is turned 'on' or 'off'. MyoD is an example of a positive regulator because it activates the transcription of genes needed for the formation of muscle tissue. Regulation of gene expression, particularly by transcription factors like MyoD, is essential for cell differentiation and the development of distinct cellular functions.