VJC H2 Bio Chpt 09 Stem Cells Notes 2024.pdf

1 VICTORIA JUNIOR COLLEGE BIOLOGY DEPARTMENT YEAR ONE LECTURE 2024 (H2 9744 & H1 8876) CORE IDEA 1: THE CELL AND BIOMOLECULES OF LIFE Stem Cells Learning Outcomes: Candidates should be able to: (t) describe the unique features of stem cells, including zygotic stem cells, embryonic stem cells and blood stem cells (lymphoid and myeloid), correctly using the terms: i. totipotency (e.g. zygotic stem cells) ii. pluripotency (e.g. embryonic stem cells) iii. multipotency (e.g. lymphoid and myeloid stem cells) (u) explain the normal functions of stem cells in a living organism, including embryonic stem cells and blood stem cells (lymphoid and myeloid) (v) discuss the ethical implications of the application of stem cells in research and medical applications and how human induced pluripotent stem cells (iPSCs) overcome some of these issues (procedural details of how iPSCs are formed are not required). Note: LO (p) – (r) in H1 syllabus Contents: Section Page Learning Outcome 1. Features of Stem Cells 2-4 LO (t) (p) in H1 8876 (a) Introduction to stem cells 2 (b) Features of Stem Cells 2 2. Types of Stem Cells and their Normal Functions 4-8 LO (u) (q) in H1 8876 (a) Zygotic stem cells 4 (b) Embryonic stem cells (Pluripotent stem cells) 5 (c) Adult Stem Cell 6 3. Ethical Implications of Stem Cells in Research and Medical Applications 9-12 LO (v) (r) in H1 8876 (a) Potential Uses of Stem Cells 9 (b) What are ethical Implications? 11 (c) Ethical implications in stem cell research 11 (d) Induced Pluripotent Stem Cells (iPSCs) 12

2 1. FEATURES AND POTENCY OF STEM CELLS LO: Describe the unique features of stem cells, including zygotic stem cells, embryonic stem cells and blood stem cells (lymphoid and myeloid), correctly using the terms: i. totipotency (e.g. zygotic stem cells) ii. pluripotency (e.g. embryonic stem cells) iii. multipotency (e.g. lymphoid and myeloid stem cells) (a) Introduction to stem cells • A stem cell is a cell from an embryo, foetus or adult that is unspecialised, and has the ability to divide for long periods ( self- renewal) or, in the case of adult stem cells, throughout the life of the organism. • It can, under certain conditions, differentiate to give rise to the tissues and organs of the body. (b) Features of Stem Cells • Stem cells differ from other kinds of cells in the body. All stem cells, regardless of their source, have the following features: (i) They are capable of dividing (mitotic cell division) and renewing themselves for long periods (long term self-renewal). (ii) They are unspecialised and are able to give rise to specialised cell types under appropriate conditions (differentiation). (i) Long term self-renewal • Stem cells are capable of making identical copies of themselves via mitotic cell divisions for the lifetime of the organism. This characteristic is referred to as self-renewal. o Stem cells may replicate many times. When cells