Unit 1 KA-1 Flashcards
What is a Stem Cell?
Unspecialised cell that can divide and the differentiate into any cell type
What is a multi-potent stem cell?
Stem cells that have the potential to make ALMOST all types of cell types found within a particular tissue.
Define pluripotent.
Pluripotent cells are embryonic stem cells that can divide/differentiate into ALL cell types
What is a Tumour?
A Tumour is a mass of cancer cells produced by excessive uncontrolled cell division.
Define Diploid and haploid.
Diploid refers to a cell having 2 sets of chromosomes
Haploid is when a cell has only 1 set of chromosomes.
What is a Germline cell?
A lineage of cells that include gametes (any sex cell) and that maintain the cells to produce gametes.
What is epithelial tissue made up of?
Epithelial cells which form the lining of the tissue of the body inside and out.
Give an definition of somatic cells.
Somatic cells are diploid and divide during growth and repair to increase and maintain total cell numbers.
What do somatic cells divide by?
Mitosis, to maintain the diploid chromosome number.
What to Germline cells divide by?
When producing more germline cells they divide by MITOSIS and when the nucleus divides to make haploid gametes (sex cells) it divides by MEIOSIS.
Why is the maintenance of chromosome complement important?
To ensure that no genetic information is lost or duplicated.
Define Meiosis.
Meiosis is a type of cell division that can only take place in the nucleus of a germline cell resulting in four haploid gametes.
Define Mitosis
Division of the nucleus of either somatic or germline cells giving two diploid daughter cells.
Define differentiation
Differentiation is the process by which a cell expresses certain genes to produce proteins characteristic for that type of cell
Identifying features of an Embryonic stem cell
Found in early embryo (blastocyst)
Pluripotent - can differentiate into all cell types
All genes can be switched on/off
Ethical concerns as use involves destruction of embryo
Identifying features of Tissue Stem Cell
Found in adult tissue
Multi-potent - Can differentiate into almost all types of cell
Not all genes can be switched on/off
Does not involve destruction of embryo
What uses do stem cells have?
Corneal repair, regeneration of damaged skin & treatment of Parkinson’s Disease, Diabetes and Alzheimer’s.
What is a benign tumour?
Cells in a tumour that stay attached to each other. Cause minimal problems in most cases and easier to remover than malignant tumours.
What is a malignant Tumour?
Cells do not remain attached to each other. The cells split off and enter the blood stream and attach elsewhere in the body causing secondary tumours.
Two characteristics of cancer cells
They divide uncontrollably and do not respond to regulatory signals.
