Cell Cycle, Differentiation & Stem Cells Flashcards
what is the cell cycle
A series of stages where body cell divide
Summarise cell cycle
• cell grows bigger / DNA replicated / organelles made
• mitosis
• cell division 2 daughter cells - mitosis
Mitosis
• used for growth & repair of cells
• 2 genetically
identical daughter cells
Prophase
• nuclear membrane breaks down
• spindle fibres form
Metaphase
• chromosomes line up at equator of cell
• spindle fibres attach to chromosomes at centromere
Anaphase
• chromatids pulled to edges of cell
• by spindle fibres
Telophase
• membrane forms around each set of chromosome
• new nuclei formed / separating them from one another
Growth
INCREASE IN:
• size of organism
• number of cells
• size of cells
measured by recording mass / length
Asexual reproduction
• 1 parent
• genetically identical
• carried out by mitosis
• faster than sexual
• no variation
What are cancer cells
• cells undergo uncontrollable + rapid cell division
• form tumours
Stem cell
• can become any type of cell
• replace damaged cells
• unspecialised
• reduce symptoms
Meristems
• stem cell
• found in plants (shoots & roots)
• mitosis occurs
How are stem cells used to treat disease
• individual has damaged cells
• stem cells stimulated to produce specialised cell required
• specialised cells injected into individual
Risks of using stem cells to treat disease
• can continue to divide + cause cancer
• may be rejected by immune system of individual
• ethical issues surrounding their use
