B2 - Cell Division Flashcards
adult stem cells
stem cells found in adults that can differentiate to form a limited number of cells such as bone marrow
cell cycle
three stage process of cell division involving mitosis and resulting to form two identical daughter cells
cloning
production of identical offspring by asexual reproduction
differentiation
process where cells become specialised for a particular function
embryonic stem cells
stem cells from an early embryo that can differentiate to form the specialised cells of the body
mitosis
middle stage of the cell cycle where one set of new chromosomes is pulled to each end of the cell forming two identical nuclei during cell division
stem cells
undifferentiated cells with the potential to form a wide variety of different cell types
therapeutic cloning
production of a genetically identical embryo to a patient so the cells can be used in medical treatments
zygote
single cell formed by the fusion of gametes in sexual reproduction
chromosome
compact DNA
46 chromosomes in a human cell
DNA
deoxynucleic acid
genetic material that codes for life and proteins
gene
section of DNA that codes to build proteins
how are zygotes formed
fertilisation of the sperm and the egg
phases of the cell cycle
interphase, mitosis, cytokinesis
interphase
DNA replication
cell carries out its functions
(80%)
Mitosis
chromosomes align at centre of cell
chromosomes are pulled apart to opposite sides of the cell by the spindle
(10%)
cytokinesis
division of cytoplasm and cell membrane to form two new cells
(10%)
why is mitosis important to living organisms
for growth and repair
why is the cell cycle needed
production of needed cells for organisms to grow and to replace and repair damaged/worn out cells
multipotent
cells that can differentiate into many different specialised cells
pluripotent
cells that can differentiate into all specialised cells
elongation
cells swelling with water and expanding
how most plants growth
meristems
tissues where growth and cell division occur
contain undifferentiated cells
organisms that reproduce asexually
fungi: spores
strawberry plants: runners
taking stem cells from the patient
injected to where they are needed
no chance of rejection
taking stem cells from a donor
can trigger immune response: high chance of rejection
can transfer infections from donor to patient
issues with adult stem cell therapy
adult stem cells are multipotent and differentiation is limited
advantages of stem cells in therapeutic cloning
lots of potential, difficult to carry out
could grow organs with no rejection issues
disadvantages/difficulties of stem cell use in therapeutic cloning
stability of egg with infused nucleus is weak
results in the destruction of an embryo after the stem cells are extracted (morality)
features of a stem cell
undifferentiated - divide by mitosis
potential sources of stem cells
aborted embryos
embryos left over from IVF
bone marrow
umbilical cord
amniotic fluid
