Studied by 0 people
Adult stem cells
stem cells that are found in adults that can differentiate and form a limited number of cells
Cell cycle
the three-stage process of cell division in a body cell that involves mitosis and results in the formation of two identical daughter cells
embryonic stem cells
stem cells from an early embryo that can differentiate to form any specialised cells of the body
Give a disadvantage of meristem
cloned plants are genetically identical, so a whole crop is at risk of being destroyed by a single disease or genetic defect
Give three advantages of adult stem cells
fewer ethical issues; adults can consent to have their stem cells removed and used
it's an already established technique for treating diseases such as leukaemia
relatively safe to use as a treatment and donors recover quickly
Give three advantages of embryonic stem cells
can treat a wide range of diseases as they can form any specialised cell
may be possible to grow whole replacement organs
usually no donor needed as they are obtained from spare embryos from fertility clinics
Give three advantages of meristem
rare species of plants can be cloned to prevent extinction
plants with desirable traits, such as disease resistance, can be cloned to produce large numbers of identical plants
fast & low-cost production of large numbers of plants
Give three disadvantages of adult stem cells
requires a donor, potentially meaning a long wait time to find someone suitable
can only differentiate into certain types of specialised cells, so can be used to treat fewer diseases
relatively safe to use as treatment and donors recover quickly
Give three disadvantages of embryonic stem cells
ethical issues arise as the embryo is potential life
risk of transferring viral infections to the patient
newer treatment so relatively under-researched, efficacy not fully confirmed
therapeutic cloning
a process where an embryo is produced that is genetically identical to the patient so the cells can then be used in medical treatments
Plant meristems
area where rapid cell division occurs in the tips of roots and shoots
Three stages of the cell cycle
1 - Interphase (cell growth and DNA replication) 2 - Mitosis (nuclear division) 3 - Cytokinesis (cytoplasm divides to form two identical cells)
Stage 2 of the cell cycle - mitosis
A complete set of chromosomes is pulled to each end of the cell and the nucleus divides to form two nuclei
First stage of the cell cycle
Cells grow bigger; (DNA) chromosomes duplicate; number of sub-cellular structures (e.g. ribosomes and mitochondria) increases
Stage three of the cell cycle
cytoplasm and cell membrane divide to form two identical daughter cells
Where are adult stem cells found?
bone marrow
Where are embryonic stem cells found?
early human embryos (usually from spare/aborted embryos from fertility clinics)
Where is meristem found?
The roots and shoots of plants
Why is there some concern around using embryonic stem cells?
They divide and grow rapidly which is ideal for cancer to form in
Type of cells that undergo cell division
Eukaryotic
Note 
Flashcard (71)