Division And Differentiation Flashcards
What is a somatic cell?
A somatic cell is any cell in the body other than cells involved in reproduction
How do somatic stem cells divide?
By mitosis
When somatic stem cells undergo mitosis, what is the product?
More somatic cells with the same diploid chromosome complement
What are germline cells?
Germline cells are gametes ( sperm and ova ) and the stem cells that divide to form gametes
How do germline stem cells divide?
By mitosis and meiosis
What organelle undergoes cell division?
The nucleus
When germline stem cells divide by mitosis what is the product?
More germline stem cells
How many pairs of chromosomes are in diploid cells?
23 pairs of homologous chromosomes, 2 sets.
When a germline stem cells undergoes meiosis, what is produced?
4 haploid gametes
What are the two divisions in meiosis? ( list steps )
Firstly, the homologous chromosomes are separated.
Secondly, the sister chromatids are separated, forming four haploid gametes.
Define cellular differentiation.
Cellular differentiation is the process by which a cell expresses certain genes to produce proteins characteristic to that type of cell. * This allows a cell to carry out specialised functions *
What are embryonic stem cells?
Embryonic stem cells are cells extracted from the early embryo / blastocyst
What is characteristic of embryonic stem cells?
Embryonic stem cells can differentiate into all the cells that make up an individual and are therefore pluripotent.
What is meant by pluripotent?
Pluripotent means a cell has the ability to express any gene, allowing the cell to differentiate into any type of cell that makes up an individual.
What are tissue stem cells?
Tissue stem cells are stem cells found within a particular tissue.
What are tissue stem cells involved in?
Tissue stem cells are involved in the growth, repair and renewal of the cells found in that tissue. Therefore they are multipotent.
What is meant by multipotent?
Multipotent means a cell has the ability to differentiate into all of the types of cell found only in a particular tissue type. * Important Example * Blood stem cells located in bone marrow can give rise to red blood cells, platelets, phagocytes and lymphocytes.
What is meant by therapeutic uses in regard to stem cells?
Therapeutic uses involve the repair of damaged or diseased organs or tissues
Give 2 examples of therapeutic uses of stem cells.
Corneal Repair
Regeneration of damaged skin
What are stem cells used for in research? ( 5 uses )
To study: * AS MODEL CELLS *
How diseases develop
Drug testing
Cellular differentiation
Gene regulation work
Cell growth
What is a specific property of stem cells?
Stem cells have the ability of self-renew under the right conditions in a lab, and are also pluripotent.
What is an ethical issue of using embryonic stem cells?
Extracting embryonic stem cells involves the destruction of embryos ( potential human life )
What is a cancer cell?
A cancer cell is an abnormal cell that does not respond to regulatory signals, and therefore divide excessively, resulting in an abnormal mass of cells called a tumour.
How are secondary tumours formed?
Cells from the initial tumour fail to attach to each other, therefore they spread throughout the body forming secondary tumours.
What is the difference between normal cells and cancer cells?
Normal cells undergo apoptosis ( programmed cell death )
Cancer cells ignore these regulatory signals and divide excessively to form tumours.
Why is it important that the chromosome complement is maintained?
To ensure that no genetic information is lost so that each daughter cell contains all of the characteristics of its species.
