B3 Cell Division Flashcards
What is a stem cell?
Undifferentiated cells that can differentiate into one or more specialised cell types
What are adult stem cells?
Stem cells from adults that can only differentiate in to a few cells
Where are adult stem cells found?
Bone marrow
What are embryonic stem cells?
Stem cells that can differentiate in to any cell
Where are embryonic stem cells found?
Early human embryos
(usually from spare embryos from fertility clinics)
What is therapeutic cloning?
Patient’s cells are used to create an early embryo clone of themselves // Then used to treat medical conditions
Advantages of therapeutic cloning
Stem cells from embryo are not rejected when transplanted
Advantage of using adult stem cells
Fewer ethical issues as its obtained from adults who can consent
Disadvantage of adult stem cells
Can take a long time to find a suitable donor
Can only differentiate in to some cells so it can treat fewer diseases
Advantages of embryonic stem cells
Can treat many diseases as it can differentiate in to many cells
Easier to obtain
Disadvantages of embryonic cells
Ethical issues
Potential risks involved with treatments, such as transfer of viral infections
What are plant meristems?
Area were rapid cell division occurs in the tips of roots and shoots
Plants stem cells
Advantages of using plant meristems to clone plants
Rare species can be cloned to avoid extinction
Plants with disease resistance can be cloned
Disadvantage of using plant meristem to clone plants
No genetic variation
(e.g an entire cloned crop could be destroyed by a disease)
What is cell division by mitosis?
Body cells divide to form two identical daughter cells
