Cell Division Flashcards
(20 cards)
What is a stem cell?
an undifferentiated cell that can differentiate into one or more specialized cell types
What are adult stem cells?
stem cells from adults can only differentiate into certain cell types
Where can adult stem cells be found?
in the bone marrow
What are embryonic stem cells?
stem cells from embryos that can differentiate into any specialized cell
Where are embryonic stem cells found?
early human embryos (usually from spare embryos from a fertility clinic)
What is therapeutic cloning?
patient’s cells are used to create an early embryo clone of themselves - stem cells from the embryo can then be used to treat the patient’s medical conditions
Give one advantage of using therapeutic cloning.
Stem cells from the embryo are not rejected when transplanted because they have the same genes as the patient
Give one advantage of using adult stem cells.
fewer ethical issues as obtained from adults who consent to their use
Give two disadvantages of using adult stem cells.
it can take a longer amount of time for a suitable donor to be found and it could only differentiate into some specialized cell types so can treat fewer diseases
Give two disadvantages of using embryonic stem cells.
there are ethical issues surrounding their use as every embryo is a potential new life and there are potential risks involving the treatments such as transfer of viral infections
Give two advantages of using embryonic stem cells.
Can differentiate into any specialized cell so can be used to treat many different diseases and they are easier to obtain as they are found in spare embryos from fertility clinics
What are plant meristems?
areas where rapid cell division occurs in the tips of roots and shoots
Give two advantages of using plant meristems to clone plants
rare species can be cloned to protect them from extinction and plants with special features can be cloned to produce many copies
Give one disadvantage of using plant meristems to clone plants.
no genetic variation, so a whole crop could be destroyed by one disease
What is cell division by mitosis?
body cells divide to form two identical daughter cells
What is the purpose of mitosis?
growth and repair of cells
What happens during the first stage of the cell cycle?
cells grow bigger, chromosomes duplicate, number of subcellular structures increases
What happens during mitosis?
one set of chromosomes is pulled to each end of the cell and the nucleus divides
What happens during the third cell cycle?
the cytoplasm and cell membrane divide, forming two identical daughter cells
What is the term for cell division in bacteria?
binary fission
