Unit 8 - Cell Division Flashcards
Interphase
Period of cell growth and DNA replication
Longest part of cell cycle
Prophase
1st stage of mitosis
DNA condenses into visible chromosomes
Nuclear membrane breaks down
Centrioles start to create spindle fibers
Metaphase
2nd stage of mitosis
Chromosomes move to equatorial plate
Spindle fibers attach
Anaphase
3rd stage of mitosis
Spindle fibers shorten
Sister chromatids pulled apart
Telophase
4th stage of mitosis
Chromosomes unravel into chromatin
Nuclear membranes reform around DNA
Cleave furrow begins to form
Cytokinesis
Happens at the same time as telophase
Cytoplasm splits
Animal cells pinch apart
Plant cells form cell plate
G1
1st stage of interphase
Cell grows
S Phase
2nd stage of interphase
“Synthesis” phase
DNA is replicated
G2
3rd stage of interphase
Cell growth, duplicate organelles, prepare for division
Sister chromatids
Replicated chromosomes attached at the centromere
Centromere
Middle part of a chromosome where sister chromatids are held together and spindle fibers attach
Asexual reproduction benefits
Quick, don’t need to find a mate, less energy-intensive, less risky, all your DNA gets passed on
Asexual reproduction drawbacks
No genetic variations, offspring are more susceptible if environmental conditions change
Sexual reproduction benefits
Genetic variation, offspring population able to adapt to changing conditions better
Sexual reproduction drawbacks
Longer, energy-intensive, time and danger in finding mates, only half of your DNA gets passed on
Binary fission
Asexual cell division in bacteria
Mitosis
Asexual cell division in eukaryotes
Daughter cells have the same number of chromosomes as parent cell
Meiosis
Sexual cell division in eukaryotes
Daughter cells have half the number of chromosomes as parent cell
Somatic cell
Body cell
Diploid (2n), two copies of every chromosome
Gamete
Sex cells (egg and sperm)
Haploid (n), one copy of every chromosome
p53
Growth regulator that stops cell from dividing if DNA is damaged
Cyclins
Proteins that encourage the cell to pass a checkpoint
Contact inhibition
Cells stop dividing if they touch each other
Mutagen
Substance that causes mutations
Mutation
Change in the DNA sequence, usually bad or causes cancer
Carcinogen
Substance that causes cancer
Equatorial plate
Middle region of the cell
Tumor
Mass of cancer cells
Cancer
Cells that divide uncontrollably
Stem cell
Undifferentiated cells
Differentiation
Process where a stem cell become a specific type of cell (e.g., muscle cell, blood cell)
Apoptosis
Programmed cell death
Surface area to volume ratio (SA:V)
Want a high SA:V so that substances can diffuse and reach the center of the cell
