cell biology - stem cells Flashcards
what is fertilisation?
when a sperm cell joins with the ovum
what is an embryo? how is it formed?
a ball of cells which has undergone mitosis from a fertilised ovum
what is a stem cell?
an undifferentiated cell which can give rise to more cells f the same type and can differentiate to form other types of cells
example of stem cells in an adult organism
bone marrow which can differentiate to form cells found in our body
what is bone marrow useful for?
medicine
how does a bone marrow transplant work?
used to treat Leukaemia which is a cancer of the bone marrow. to treat:
- patients existing bone marrow is destroyed
- then receives a transplant of bone marrow from a donor
- stem cells in the bone marrow now divide and form new bone marrow. also differentiate and form blood cells
what are the problems with a bone marrow transplant?
- donor has to be compatible with patient, otherwise white blood cells produced by donated bone marrow could attack patient’s body
- risk of viruses can be passed from the donor to the patient
how does stem cells help therapeutic cloning?
in therapeutic cloning, embryo produced with same genes as patient.
stem cells from embryo can be transplanted into patient without being rejected by the patient’s immune system. once inside patient, stem cells can differentiate to replace cells which have stopped working correctly
what is therapeutic cloning useful for?
range of medical conditions such as diabetes and paralysis
what are the objections to therapeutic cloning?
religious and ethical
what are the two ways that adult stem cells are useful in medicine?
therapeutic cloning and bone marrow transplant
what tissues do roots and buds of a plant contain?
meristem - can differentiate into any type of plant tissue, at any point in the life of a plant
what is meristem tissue used for?
- to clone a rare plant to stop it from going extinct very quickly or produce cloned crops for farmers
