B2 - Cell Division Flashcards
What are stem cells?
Stem cells are unspecialised cells that turn into specialised cells.
Where are embryonic stem cells found?
Inside the embryo. These are called embryonic stem cells.
Where are stem cells found in plants?
They are found in the meristem
Where are adult stem cells found?
Mainly in bone marrow but also in small amounts in tissue in your body. Adult stem cells can only turn into some of the specialised cells.
Can human stem cells re-differentiate?
No. Only plant stem cells can re-differentiate.
List some of the uses of stem cells?
- they can be used to clone new organs that will not be rejected by the body
- they can potentially heal some injuries like spinal damage
- they can help fix the immune system
Why do some people think that stem cell research is unethical?
Because stem cells are harvested from dead foetuses.
What is the cell cycle?
The process of a cell replicating and splitting itself
What are the 3 stages of the cell cycle called?
Interphase
Mitosis
Cytokinesis
What is interphase?
This is where the cell replicates its DNA and its sub-cellular structures
What is mitosis?
- all the chromosomes line up in the middle cell
- the original cells move to one side and the replicants to the other
- the nuclei separate forming 2 separate identical nuclei
What is cytokinesis?
This is where the cytoplasm splits down the middle of the cell forming 2 separate identical daughter cells.
How long does the cell cycle take?
I varies depending on the amount of DNA and sub-cellular structures needed to be cloned and the size of the cell
Give 3 ethical problems with stem cells
- Come from aborted foetuses
- Embryo can’t give permission
- Religion can prevent interferance in reproduction
