1What is a stem cell?
An unspecialised cell capable of self-renewal and differentiation
2What roles do stem cells play in the body?
Development, tissue maintenance, and repair
3Why are stem cells considered potential therapeutic agents?
They can restore or replace damaged tissues
4How many broad types of stem cells are described?
Four
5What are the four main types of stem cells?
Adult, embryonic, umbilical cord, and induced pluripotent stem cells
6What are the two key properties of stem cells?
Self-renewal and differentiation
7What is self-renewal?
Stem cells dividing to produce more stem cells
8What is differentiation?
Stem cells becoming specialised cell types
9What are adult stem cells?
Tissue-specific stem cells that persist after development
10What limitation do adult stem cells have?
They may be difficult to locate or isolate
11What are embryonic stem cells?
Stem cells produced very early in development
12What is a key property of embryonic stem cells?
They can differentiate into almost any tissue
13Where are embryonic stem cells located in early development?
The inner cell mass of the blastocyst
14What is the ultimate totipotent cell?
The fertilised egg (zygote)
15What does totipotent mean?
Able to produce an entire organism (all cell types including extra embryonic tissues)
16When are cells typically totipotent in development?
Early embryo (about 1–3 days)
17What does pluripotent mean?
Able to differentiate into almost any body cell type (but not a whole organism)
18Which cells are pluripotent?
Embryonic stem cells and embryonic germ cells
19When are cells typically pluripotent in development?
Blastocyst stage (about 5–14 days)
20What are embryonic germ (EG) cells?
Pluripotent stem cells derived from fetal tissue
21What are umbilical cord stem cells?
Stem cells obtained from umbilical cord blood and umbilical cord tissue
22What is Wharton’s jelly?
Gelatinous tissue of the umbilical cord that contains mesenchymal stem cells
23When are umbilical cord stem cells collected?
Before or immediately after birth
24What type of stem cells dominate umbilical cord blood?
Haematopoietic stem cells
25Why are umbilical cord stem cells clinically useful?
They can be an alternative source to bone marrow stem cells
26What are induced pluripotent stem cells (iPSCs)?
Adult somatic cells artificially reprogrammed to a pluripotent state
27What is the key idea behind iPSC technology?
Reprogramming differentiated cells back into a stem-cell-like state
28What is a stem cell niche?
The specific microenvironment where stem cells are maintained
29Where are haematopoietic stem cells located?
Bone marrow
30What is the function of haematopoietic stem cells?
To produce all blood cell types
31What two major lineages arise from haematopoietic stem cells?
Myeloid and lymphoid lineages
32Which cells arise from the myeloid lineage?
Red blood cells, platelets, macrophages, neutrophils, eosinophils, basophils, osteoclasts
33Which cells arise from the lymphoid lineage?
T cells, B cells, natural killer cells, dendritic cells
34What is stem cell therapy?
The use of stem cells to treat disease or injury
35What is human development?
The process from fertilised egg to embryo, foetus, and adult
36What are the earliest stages of human development?
Embryonic stages
37What follows embryonic development?
Foetal development
38What drives the developmental pathway?
Gene-regulated processes
39What controls genome expression during development?
Developmental gene regulation
40What is a blastocyst?
An early embryo containing an inner cell mass and outer cell layer
41What is implantation?
Embedding of the embryo into the uterine lining
42What is gastrulation?
Formation of the three germ layers in the embryo
43What are the three germ layers?
Ectoderm, mesoderm, and endoderm
44What does ectoderm develop into?
Nervous system and skin
45What does mesoderm develop into?
Muscle, skeleton, kidneys, and reproductive system
46What does endoderm develop into?
Endocrine glands, lungs, digestive tract, and liver
47What is organ formation?
The process by which organs develop during embryogenesis
48What is meant by a gene-driven body plan?
Genes determine overall body structure and patterning
49What cellular processes are required for development?
Cell movement, protein synthesis, cell division, cell signalling, apoptosis, and gene regulation
50What role does apoptosis play in development?
Programmed cell death to shape tissues and organs
51What is limb development controlled by?
Specific developmental genes
52Why is circulatory development critical?
Enables transport of oxygen and nutrients
53What factors can affect embryo and foetus development?
Environmental, genetic, and lifestyle agents
54How can the unborn baby be monitored?
Ultrasound, genetic screening, and blood tests
55What is a key conclusion about stem cells?
They have different capacities and essential roles in development and homeostasis