Cell Division Flashcards
(25 cards)
Uses of mitosis
Growth and repair of tissues
Asexual reproduction
Making of white blood cells
Making new stem cells
Making gametes but only from one haploid n cells
Main parts of cell cycle
G1)
S >interphase
G2)
Mitosis
Cytokinesis
What happens in G1
Growth
Protein synthesis
Organelles copied
What happens in S
DNA copied
What happens in G2
Growth
Aerobic respiration
ATP
What is GO
When a cell is no longer dividing
Cell has differenciated
Cells DNA is damaged
Cell is old
Name cell cycle checkpoints and their purpose
G1, S, G2 check points and metaphase check point
Check cell is correct size and has correct nutrients
Check DNA has no mistakes
Check chromosomes are in correct place
What do diploid and haploid mean
Diploid=2n (chromosomes in homologous pairs)
Haploid=n (no pairs)
What makes a chromosome a homologous pair
One maternal
One paternal
Same genes in same place
Same size
Centromere in Same place
Why is a root tip squash used to see stages of Mitosis under a microscopes
What stains are used
Root tip has meristem so cell division is happening
No chloroplasts
Squashed to give a thin layer for light to pass through
Stain= methelyne blue/acetic orecin
Prophase
Chromosomes coil up and are visible
Nuclear membrane breaks down
Ventricles move to poles of cell and spindle fibres start to form
Metaphase
Spindle fibres attach to centromere and move chromosomes to the equator of the cell
Anaphase
Spindle fibres shorten
Chromatids pulled apart (now chromosomes)
Centromere breaks
Chromosome number doubles
Chromosomes pulled to the poles
Telophase
Nuclear membranes form
Chromosomes uncoil into chromatin
Nucleolus is formed
Cytokinesis
This is the cytoplasm divides between telophase and interphase
Cytokinesis in animals
A ring of contracting proteins actin and myosin attached to cell surface membrane contracts to form cleavage furrows until it pinches the cells apart
Cytokinesis in plant cells
Vesicles move to middle of cell and fuse to form cell plate
Cellulose is added via exocytosis to form cell wall
How do yeast perform asexual reproduction
They do budding bulge on side of the cell
Mitosis of nucleus happens
A nucleus and other organelles move into bulge
Bulge pinches off
Which organisms do Asexual reproduction by Mitosis
Strawberry plants
Potatoes
Hydra
Amoeba
Binary fission
Asexual reproduction in bacteria
NOT Mitosis as they have no nucleus and no chromosomes
Define a stem cell
Undifferentiated/unspecialised cells
Do Mitosis
Can differnciate into other cell types
Once specialised can no longer divide
What are totipotent cells
Stem cells that can form all types of cell and therefore the entire organism
Early embryo 8-16 cells
Pluripotent cells
Stem cells that can form all tissue types but not the entire organism
Embryo more then 16 cells
Multipotent cells
Stem cells that can only form particular tissue types
Found in bone marrow and umbilical coed as well as in many organs
