Which of these statements best describes stem cells?
(A) Adult stem cells but not embryonic stem cells are immortal in lab culture.
(B) Only embryonic stem cells are found in every tissue of the adult body.
(C) Embryonic stem cells and induced pluripotent stem cells give rise to all the different types of cells in the organism.
(D) Stem cells can be isolated from the inner cell mass of blastocytes, bone marrow, and amniotic fluid, but not from adipose tissues.
The correct answer and explanation is :
The correct answer is (C) Embryonic stem cells and induced pluripotent stem cells give rise to all the different types of cells in the organism.
Explanation:
Stem cells are unique cells capable of self-renewal and differentiation into specialized cell types. There are different types of stem cells, including embryonic stem cells (ESCs), adult stem cells (ASCs), and induced pluripotent stem cells (iPSCs).
- Embryonic stem cells (ESCs) are derived from the inner cell mass of the blastocyst (an early-stage embryo) and are pluripotent, meaning they can give rise to all three germ layers: ectoderm, mesoderm, and endoderm. This means they can differentiate into any cell type in the body, making them highly valuable for regenerative medicine and research.
- Induced pluripotent stem cells (iPSCs) are somatic (differentiated) cells that have been genetically reprogrammed to an embryonic-like pluripotent state using transcription factors (such as Oct4, Sox2, Klf4, and c-Myc). Like ESCs, they can generate all types of cells in an organism.
- Adult stem cells (ASCs) are found in various tissues (such as bone marrow, adipose tissue, and the brain) but are multipotent, meaning they can only differentiate into a limited range of cell types related to their tissue of origin.
Why Other Options Are Incorrect:
- (A) Incorrect: Embryonic stem cells, not adult stem cells, are immortal in lab culture. Adult stem cells have limited self-renewal.
- (B) Incorrect: Embryonic stem cells are not found in adult tissues; adult stem cells reside in specific tissues and are multipotent.
- (D) Incorrect: Adipose tissue does contain stem cells (adipose-derived stem cells or ADSCs), making this statement false.
Stem cells, including cancer stem cells, share characteristics such as self-renewal and differentiation, contributing to tumor growth and resistance to therapy.
Here is an infographic illustrating different types of stem cells, including embryonic stem cells (ESCs), adult stem cells (ASCs), and induced pluripotent stem cells (iPSCs) along with their differentiation potential.