With reference to ‘stem cells’, frequently in the news, which of the following statements is/are correct? 1. Stem cells can be derived from mammals only. 2. Stem cells can be used for screening new drugs. 3. Stem cells can be used for medical therapies. Select the correct answer using the codes given below :

Stem cells are undifferentiated cells capable of self-renewal and differentiation into specialized cell types [2]. Statement 1 is incorrect because stem cells are not exclusive to mammals; they are found in various multicellular organisms, including simple animals like Hydra and Planaria, which use specialized cells for regeneration. Statement 2 is correct as stem cells, particularly embryonic and induced pluripotent stem cells (iPSCs), are extensively used for screening new drug candidates and toxicity assessment in vitro [3]. Statement 3 is correct because stem cells are central to regenerative medicine and medical therapies, such as bone marrow transplantation for leukemia and experimental treatments for spinal injuries and diabetes [5]. These cells offer potential for replacing damaged tissues and organs across a range of human diseases [5]. Therefore, only statements 2 and 3 are correct.

Sources

1. [1] https://pmc.ncbi.nlm.nih.gov/articles/PMC4009932/
2. [2] Science , class X (NCERT 2025 ed.) > Chapter 7: How do Organisms Reproduce? > 7.2.3 Regeneration > p. 116
3. [3] https://www.nature.com/articles/s41392-024-01809-0
4. [5] https://www.nature.com/articles/s41421-025-00852-7