KA1 Division And Differentiation Flashcards
What are embryonic stem cells
- They are pluripotent
* Can specialise into all cell types that make up a individual
What is corneal repair
Stem cells are injected into or washed over the eyes surface
Signals from the body instruct the stem cells to specialise into corneal cells
What are the stages of mitosis
Chromosomes duplicate- end up with 2 identical chromatids
They line up at the equator
The spindle fibres pull part the chromatids
The cytoplasm splits and end up with 2 new diploid cells
What are examples of specialised eggs
The liver
Hyaline cartilage
Devision of the egg
Where are stem cells found
Embryos
Adult tissues eg bone marrow
What are the therapeutic uses of stem cells
They repair damaged/diseased organs/tissues
Used in corneal repair
Can regenerate damaged skin for use in skin graphs
What are features of somatic cells
- Have 46 chromosomes
- Not in reproduction
- They decide by mitosis to self renew and main the diploid chromsome number
- They make up the body organs
What are features of germline cells
They are sex cells
Found in ovaries in females and testes of males
Divide by mitosis to form for germline cells-diploid cells
Divide by meiosis to form gametes-haploid cells(egg or sperm)
Why might people be against the use of embryonic stem cells
We should not mess with human life
Humans should not be trying to play god
Stem cells can maybe lead to cloning humans
Why are stem cells used in research
Provide information on cell growth, differentiation and gene regulation
Used as model cells to investigate how diseases develops and for drug testing
What is regeneration of damaged skin
Stem cells are grown on a scaffold and are used to express the genes specific to a skin epitheral
What is differentiation
When a cell develops more specialised function by expressing the genes for that cell type
How does differentiation effect genes in a cell
Certain genes are switched off so the cell only expresses the required genes
What are adult tissue stem cells
They are involved in growth, repair and renewal
They are multipotent meaning they are limited in potential and are only able to specialise into particular tissue types
What are cancer cells
•abnormal cells that do not respond to the regulatory signals in the body
•which lets them avoid ong detsryoyed by the immune system
This allows them to divide excessively and form a tumour
