Stem Cells Flashcards
What are stem cells?
Stem cells are unspecialised cells
What are stem cells able to do?
Stem cells are able to differentiate into a diverse range of specialised cells
Types of stem cells
Embryonic and Adult Tissue
Where do embryonic stem cells come from?
Embryonic stem cells are derived from a 4-5 day old embryo (blastocyst)
What are embryonic stem cells able to do?
Embryonic stem cells are able to differentiate into all types of cells that make up an organism (pluripotent)
Where do adult tissue stem cells come from?
Adult tissue stem cells are found in small numbers in the tissue and organs of adults and children
What are adult tissue stem cells able to do?
Adult tissue stem cells are able to differentiate into a limited number of cell types that are closely related to the nearby tissue (multipotent)
Selective gene expression
Differentiated cells only express the genes that code for the proteins specific to the workings of that particular cell
How does selective gene expression work?
The genes that don’t code for the proteins needed are turned off and the genes that are needed are turned on
What are somatic cells?
Somatic cells are differentiated cells that form the different types of body tissue that exist
How do somatic cells divide?
Somatic cells divide by mitosis for growth and repair
Examples of somatic cells
Red blood cell and smooth muscle cell
What are germline cells?
Germline cells include the gametes and the cells that produce the gametes
How do germline cells divide?
Germline cells divide by mitosis. Gamete mother cells divide by meiosis to produce gametes
Examples of germline cells
Sperm and eggs
Germline mutations
Mutations in germline cells are passed on to offspring
Somatic mutations
Mutations in somatic cells are not passed on to offspring
What is a tumour?
A mass uncontrollable cell division
What is a haploid?
A haploid is a cell containing 1 set of chromosomes (23)
What is a diploid?
A diploid is a cell containing two sets of chromosomes (46)
What is mitosis?
Mitosis is the process of cell division where 2 identical diploids are produced
What is meiosis?
Meiosis is the process of cell division where 4 identical haploids are produced
Therapeutic uses of stem cells
- Treat leukimia
- Make new bone cells
- Nerve cells to heal spinal cord injuries
- Taken from someone with heart disease to be turned into heart tissue
- Stem cell grafts for cornea repair
- Study diseases
- Drug testing
- Trachea (windpipe) transplant
What are cancer cells?
They are cells that do not respond normally to regulatory signals and divide excessively to produce a mass of abnormal cells
Benign tumour
Cancer cells continue to reproduce a mass of abnormal cells
Malignant tumour
Lose molecules on their surface that would normally hold them in place and can therefore be detached from their neighbours, causing the cells to spread
