Cell division Flashcards
What is inside the nucleus
Chromosomes
What do chromosomes carry a large amount of
Genes
What are the names of the 3 stages of mitosis
Interphase, mitosis, cytokinesis
What happens during interphase
Cell grows bigger
DNA replicated
Increase in number of sub-cellular structures like mitochondria and ribosomes
What happens during mitosis (2nd phase)
A complete set of chromosomes is pulled to each side
Nucleus divides into two
What happens during cytokinesis
Cytoplasm and cell membrane divide to form two identical daughter cells
Why is mitosis important
Growth and repair of cells
What is stem cell
Undifferentiated cell that can differentiate into any type of cell
What can adults stem cells differentiate into
Only certain types often ones from where they were removed from
Where are adults stem cells found
Bone marrow
What are advantages of adult stem cells
Fewer ethical issues
Established technique for treating leukaemia
Relatively safe to use
Donors recover quickly
What are the disadvantages of adult stem cells
Requires donor which can take a long time
Can only differentiate into a few types of cell
What can embryonic cells differentiate into
Any type of specialised cell
Muscle, nerve cell etc
Where are embryonic stem cells found
Early human embryos
What are the advantages of embryonic stem cells
Treat a wide range of disease
Possible to grow whole replacement organ
No donor needed
What are disadvantages of embryonic stem cells
Ethical issues - potential life is destroyed
Risk of transferring viral infections
Under researched as it is new
What can plant meristems differentiate into
All cell types
Can clone entire plant
Where are plant meristems found
Meristem regions in roots, shoots of plant
Disadvantage of meristems
Cloned plants will be genetically identical so whole crop could be destroyed by a disease
Advantage of meristem
Rare species can be cloned to stop extinction
Plants with desirable traits like disease resistance can be cloned
Fast and low cost
Explain therapeutic cloning
Cells from patient’s body are used to create a cloned embryo of themselves
Stem cells form this embryo can be used for medical treatments
Stem cells have same genes as patient so are less likely to be rejected
