Stem cells Caq

🩻 Stem cells Created Tags Describe the difference in potency of Totipotent and pluripotent Totipotent stem cells can differentiate into all cell types including extra- embryonic tissues while pluripotent stem cells has the potential to differentiate into almost any cell types except extra embryonic tissue DO NOT WRITE PLACENTA as it is a subset of the extra embryonic tissues Totipotent stem cells can organise into an entire organism but pluripotent stem cells lack self-organising ability to form an entire organism Describe the normal functions of blood stem cells in a living organism Undergo self renewal to maintain its population of cells/ provide continuous supply of blood stem cells Can differentiate into blood cells to replace worn out/damaged cells Blood stem cells include myeloid and lymphoid stem cells Lymphoid stem cells can differentiate into lymphocytes such as B cells and T cells Myeloid stem cells can differentiate into red blood cells, neutrophils,eosinophils,basophil,monocytes,platelets Mistakes Do not provide functions of specialised blood cells Jul y 14 , 2025 1113 AM St em cells 1

Ethical issues of ipc Procedure Of harvesting ES cells destroy the embryo which has the potential to develop into a full-sized organism/ akin to taking a human life Intentional creation of embryos with the intention of using them for research and destroying them in that process is considered active killing and violates respect for nascent human life; Harvesting of oocytes R! embryos is invasive/painful retrieval from the women / / Medical risk of oocyte reducing the number and possibly the quality of remaining oocyte for future reproductive purposes Increasing risk of exploitation of women for commercial benefits; Informed consent of donors of surplus ES cell lines from frozen embryos from IVF may not be obtained / donors may not fully understand the implications of the donation/confidentiality of the donor may not be protected;/Patient may not fully understand the moral issue arising from the use of stem cell for their consent; ES cells from donor may exhibit unknown long term effects that range from incompatibility to tumor formation in recipient and recipient may not fully understand the implications; Technologies used to produce stable stem cell lines can be licensed and patented by the biotechnology companies, only the rich has access to and can afford the stem cell therapies that come with high costs; Creation of ES cells using nonhuman oocytes may give rise to chimeras that appear part human and part animal / have characteristics of both humans and animals; The implantation of human stem cell into animals during experimentation may cause development of human part on animalsʼ; Defining features of stem cells Able to undergo self-renewal by mitotic cell division Unspecialised/not terminally differentiated St em cells 2

Able to undergo differentiation/ able to produce specialised cells Describe the features and normal functions of stem cells in human Embryonic stem cells Pluripotent Found in inner cell mass of blastocyst Can differentiate into different types of cells that develop from the 3 germ layers from which all the cells of the body arise Myeloid stem cells are undifferentiated and unspecialised cells Multi potent, able to differentiate into specialised cells Capable of self-renewal by mitotic cell division to ensure a constant pool of stem cells for growth and development Their ability to differentiate into specialised cells helps to replace cells lost due to cell death and injury Able to differentiate to give various blood cells and except lymphocytes such as red blood cells, neutrophils, eosinophils, basophils, mast cells, macrophages, dendritic cells and platelets Lymphoid stem cells Multi potent Capable of self renewal by mitotic cell division Able to differentiate to give lymphocytes such as B cells T cells and natural killer cells Compare myeloid and lymphoid stem cells Myeloid Lymphoid Range of cell types that it can Differentiate to giver a larger range of cell types like all blood Differentiaite to give a smaller range of cell types like St em cells 3

Myeloid Lymphoid differentiate into cells except lymphocytes lymphocytes Examples of specialised cells differentiated from stem cells Red blood cells, neutrophils, eosinophils, basophils,mast cells, macrophages, dendritic cells and platelets B cells at cells amd natural killer cells Type of immune response Innate immunity Adaptive immunity Circulated Form RBC that are circulated in blood Form lymphocytes that are circulated in the lymph Both are blood stem cells derived from haematopoietic stem cells in the bone marrow Both are multi potent and can differentiate to a limited range of cells under their lineage Advantages of asymmetrical division allows stem cells to produce one daughter stem cell that is identical to the parental stem cell ensuring a constant pool of stem cells And one progenitor cell that is only capable of differentiating into related specialised cell type, increasing population of specialised cells in a specific tissue How ESCs are extracted Extract egg cells from female and sperm cells from male Fuse or fertiliser the egg cell with sperm cell outside of the body or in culture Extract our the inner cell mass of blastocysts Describe how iPSCs overcome some ethical issues associated with medical use of stem cells in human No need to destroy embryos for extraction or pluripotent stem cells and hence not regarded as killing a life due to some views that embryos are viable living St em cells 4

organism Avoid issues or donor consent Derived directly from patients adult cellls and hence not regarded no foreign tissues that may lead to tissue reject or immune response and no need for immunosuppressed drugs Explain how introduction of synthetic mRNA can produce iPSCs/ why are transcription factors needed for production of iPSCs Translation of synthetic mRNA will produce proteins which are needed to switch off certain genes in specialised adult cells allowing them to de- differentiate And switch on expression of certain specific stem cell genes allowing adult somatic cells to achieve pluripotency Proteins such as transcripts factors like repressors and activators bind to silencer and enhancer respectively Needed to alter gene expression patterns of cells such that it is similar to that of embryonic stem cells resulting in production of iPSCs St em cells 5