Division and differentiation of human cells Flashcards
What is differentiation?
The process by which a cell develops more specialised functions by expressing the genes characteristic for that type of cell.
Changes to cells that allow them to specialise for different functions.
What are stem cells?
Unspecialised somatic cells that can divide to make copies of themselves (self-renew) and to make cells that differentiate into specialised cells of one or more types.
What does the term ‘Pluripotent’ mean?
Stem cell that has the potential to make almost all differentiated cell types of the body.
The cells of the early embryo are pluripotent.
The cells of the early embryo can be cultured in the laboratory to give a supply of embryonic stem cells.
What is the meaning of the term ‘Multipotent’
Stem cells that can make almost all of the cell types found in a particular tissue type.
Tissue (adult) stem cells are multipotent.
Tissue stem cells are involved in the growth, repair and renewal of the cells found in that tissue.
What types of cells can tissue stem cells in bone marrow differentiate into?
Red blood cells, platelets, phagocytes and lymphocytes.
What type of cells are Somatic Cells?
Diploid cells containing two sets of homologous chromosomes.
Diploid cells in humans have 23 pairs of homologous chromosomes.
By which process to somatic cells divide by?
Somatic cells divide by mitosis to maintain the diploid chromosome number.
Somatic cells divide by mitosis to form more somatic cells which differentiate to form different body tissue types.
Give four examples of basic types of human tissue.
Epithelial tissue, connective tissue, muscle tissue and nervous tissues.
True or false: Mutations in somatic cells can be passed onto offspring.
False.
By which process(es) can Germline Cells divide by?
Germline Cells can divide by mitosis to produce more Germline cells.
Germline Cells can divide by meiosis to produce haploid gametes.
True or false: mutations in Germline Cells can be passed onto offspring.
True.
Research and therapeutic uses of stem cells include:
The repair of damaged or diseased organs or tissues eg corneal transplants and skin grafts for burns.
Stem cells can also be used as model cells to study how diseases develop or for drug testing.
Name an ethical issue related to stem cell use.
It forces us to choose between the duty to prevent or ease suffering and the duty to respect the value of human life.
Name two characteristics of cancer cells.
- Cancers cells divide excessively to produce a mass of abnormal cells.
- Cancer cells do not respond to regulatory signals
How are secondary tumours formed?
Cancer cells fail to attach to each other and spread through the the body in the bloodstream.
