KA1- Division And Differentiation In Human Cells Flashcards
Somatic cell
A somatic cell is any cell in the body other than cells involved in reproduction
Division of somatic cells
Somatic stem cells divide by mitosis to form more somatic cells
Germline cells
Germline cells are gametes (sperm and ova) and the stem cells that divide to form gametes
Division of germline cells
Germline stem cells divide by mitosis and by meiosis
Division by mitosis produces more germline stem cells
Division by meiosis produces haploid gametes
Mitosis of germline stem cells
The nucleus of a germline stem cell can divide by mitosis to maintain the diploid chromosome number. Diploid cells have 23 pairs of homologous chromosomes
Meiosis of germline stem cells
The nucleus of a germline stem cell can divide by meiosis. It undergoes 2 divisions, firstly separating homologous chromosomes and secondly separating chromatids. Haploid gametes contain 23 single chromosomes.
Cellular differentiation- embryonic stem cells
4 from essay
All the genes in embryonic stem cells can be switched on so these cells can differentiate into any type of cell
Cellular differentiation- tissue stem cells
5 from essay
Tissue stem cells are multipotent as they can differentiate into all the types of cells found in a particular tissue type. Point 6.
Research uses of stem cells
Research uses involve stem cells being used as model cells to study how diseases develop or being used for drug testing
Stem cell research provides information on how cell processes such as cell growth, differentiation and gene regulation work
Cancer cells
Cancer cells divide excessively because they do not respond to regulatory signals. This results in a mass of abnormal cells called a tumour.
Secondary tumours
Cells within the tumour may fail to attach to each other, spreading through the body where they may form secondary tumours.
