Division And Differentiation Of Human Cells Flashcards
(21 cards)
What is the term to describe stem cells?
They are unspecialised cells
What two things can stem cells do?
They can self renew (reproduce to produce more stem cells), remaining undifferentiated
They can differentiate into specialised cells
What are somatic cells?
They are any cell in the body other than cells involved in reproduction(not involved in reproduction)
Examples- muscle, blood, skin, bone
How many sets of chromosomes do somatic cells have? What is this called?
They have two sets of chromosomes(46)
They are diploid cells
What process to somatic stem cells divide by? What do they form?
They divide by mitosis to form more somatic cells(daughter cells that both have 46 chromosomes)
What are germline cells?
They’re gametes(sperm and ova) and the stem cells that divide to form gametes
What processes do germline stem cells divide by?
Mitosis and meiosis
What happens when germline stem cells divide by mitosis?
How many pairs of homologous chromosomes do diploid cells have?
They divide by mitosis to produce more germline stem cells
The nucleus of a germline stem cell can divide by mitosis to maintain the chromosome diploid number
Diploid cells have 23 pairs of homologous chromosomes
What happens when germline stem cells divide by meiosis?
What does meiosis produce?
They divide by meiosis to produce haploid gametes
The nucleus undergoes two divisions
1) firstly separating homologous chromosomes
2) secondly seperating chromatids
This produces haploid gametes(4) containing 23 single chromosomes
What are homologous chromosomes?
When one chromosome is inherited from the male and one form the female
What is cellular differentiation?
What does it allow a cell to do?
The process by which a cell expresses certain genes to produce a protein characteristic for that type of cell
This allows a cell to carry out specialised functions
What are embryonic stem cells?
What term can you use to describe these stem cells?
Cells in the very early embryo that can differentiate into all cell types that make up the individual
They are pluripotent
What can happen to genes in an embryonic stem cells?
All the genes in an embryonic stem cell can be switched on so these cells can differentiate into any cell type
What are tissue stem cells?
What term can you use to describe them?
Can you give an example?
Cells that are involved in the growth repair and renewal of the cells found in that tissue
They’re multipotent
Example- blood stem cells in bone marrow can give rise to red blood cells, phagocytes, lymphocytes and platelets
What do therapeutic uses of stem cells involve?
What are two examples?
The repair of damaged or diseased organs or tissues
This includes corneal repair and the regeneration of damaged skin
What does research of stem cells involve?
Stem cells being used as model cells to study how diseases develop or being used for drug testing
What does stem cells involve research provide?
Information on how cell processes like cell growth, differentiation and gene regulation work
What can stem cells from the embryo do under the right conditions?
Self renew
What are the ethical issues surrounding embryonic stem cells?
Their use can offer effective treatments for disease and injury however it involves the destruction of embryos
Discuss how cancer cells result in a tumour
Cancer cells divide excessively because they fail to respond to regulatory signals, such his results in a mass of abnormal cells called a tumour
What happens when tumour cells fail to attach to each other
If tumour cells fail to attach to each Föhr they can spread throughout the body where they may form secondary tumours
