Scientists have recently developed a process by which a skin cell from a human can be triggered to develop into a human heart muscle cell. This is possible because                   . a. most cells in the human body contain the genetic instructions for making all types of human cells; b. a skin cell is produced when all genes in the cell are expressed; turning off some genes in the cell results in a heart cell; c. scientists can add new genes to old cells to make them take different forms; d. a skin cell expresses only recessive alleles, so it can be triggered to produce dominant heart cell alleles; e. it is easy to mutate the genes in skin cells to produce the alleles required for other cell types

Verified step by step guidance

1. Understand the concept of cellular differentiation: Cellular differentiation is the process by which a less specialized cell becomes a more specialized cell type. In humans, most cells contain the same genetic material (DNA), but different cell types express different sets of genes to perform specific functions.
2. Recognize that all human cells (except red blood cells) contain the complete set of genetic instructions (the genome). This means that a skin cell has the genetic potential to become any other type of cell, including a heart muscle cell, if the correct genes are activated or suppressed.
3. Learn about induced pluripotent stem cells (iPSCs): Scientists can reprogram specialized cells, like skin cells, into a pluripotent state where they behave like stem cells. These iPSCs can then be directed to differentiate into specific cell types, such as heart muscle cells, by controlling gene expression.
4. Evaluate the options provided in the question: Option (a) aligns with the concept that most cells contain the genetic instructions for making all types of human cells. This is the basis for reprogramming skin cells into heart muscle cells.
5. Understand why the other options are incorrect: For example, option (b) incorrectly suggests that turning off genes in a skin cell directly results in a heart cell, which oversimplifies the process. Option (c) implies adding new genes, which is not necessary since the genetic instructions are already present. Option (d) and (e) involve misconceptions about alleles and mutations that are not relevant to this process.

Key Concepts

Cell Differentiation

Cell differentiation is the process by which a less specialized cell becomes a more specialized cell type. In multicellular organisms, this process allows for the development of various cell types, such as muscle cells, nerve cells, and skin cells, each with distinct functions. Understanding how cells can change their identity is crucial for grasping how a skin cell can be transformed into a heart muscle cell.

Gene Expression

Gene expression refers to the process by which information from a gene is used to synthesize functional gene products, typically proteins. Different cell types express different sets of genes, which determines their specific functions. In the context of the question, manipulating gene expression in a skin cell can enable it to adopt the characteristics of a heart muscle cell.

Stem Cells and Induced Pluripotent Stem Cells (iPSCs)

Stem cells are undifferentiated cells that have the potential to develop into various cell types. Induced pluripotent stem cells (iPSCs) are a type of stem cell created by reprogramming adult cells, such as skin cells, to revert to a pluripotent state. This technology allows scientists to generate specific cell types, like heart muscle cells, from differentiated cells, highlighting the potential for regenerative medicine.