Mitosis and The Cell Cycle

Mitosis - part of eukaryotic cell division during which the cell nucleus divides

Cell cycle - series of events in which a cell grows, prepares for division, and divides to form two daughter cells

3 phases of interphase are - G1, S, G2

G1 phase - stage of interphase in which cell grows and performs its normal functions

S phase - The synthesis phase of the cell cycle; the portion of interphase during which DNA is replicated.

G2 phase - stage of interphase in which cell duplicates its cytosol and organelles, preparing for cell division

Why does DNA replicate? - To maintain the same amount of DNA in each daughter cell after the cell divides during mitosis.

What are the phases of mitosis? - prophase, metaphase, anaphase, telophase

Prophase (Pro goes .....) (....Poof!) - Chromosomes become visable (coil/condense), nuclear membrane/nucleolus dissolves, spindles and centrioles forms

Early Prophase vs Late Prophase

Metaphase (Meta means....) - (.....Middle!) the chromosomes line up across the equator of the cell

Anaphase (A for...) (...a part and away!!) - the sister chromatids separate and move to opposite ends of the cell (division of the centromere)

Telophase (T for ...) (...two nuclei!!) - the chromatids/chromosomes uncoil, nuclear membrane and nucelolus reform, spindle fibers and centrioles break down, and two nuclei are formed. Hint: it is the opposite of prophase

Cytokinesis - division of the cytoplasm

Phases of the cell cycle in order - interphase (G1, S, G2), (Mitosis) prophase, metaphase, anaphase, telophase, cytokinesis

Phases of mitosis in order - prophase, metaphase, anaphase, telophase

Cancer - any malignant growth or tumor caused by abnormal and uncontrolled cell division

cytokinesis in plant cells cell plate forms

cytokinesis in animals - cleavage furrow constricts like a drawstring to separate the cells

Cancerous cells cause the cell cycle to speed up because they spend less time in interphase.

Why do cells divide? - growth, repair, healing, to make more cells

What happens if a cell doesn't divide? - 1. slower communication (DNA overload)

2. inability to move waste out and nutrients in efficiently. (surface area restrictions)

3. Slower diffusion

Which increases faster, volume or surface area? - volume

What happens to the surface area to volume ratio when the cell becomes too large? - It decreases (making it harder for the cell to function)

Which cells have a higher surface area to volume ratio? - Small ones

What is a factor that regulates the cell cycle? (Ensures checkpoints are met: Was DNA replicated? Is the cell large enough? Are all chromosomes in the middle of the cell?) - Cyclin - dependent kinase

programed cell death is called - apoptosis

Apoptosis is normal. Why do some cell program their own death? - To stop cancerous cells from dividing, to rid a mutation that was not fixed

What would happen if a cell went through cytokineses before mitosis? - Daughter cells would lack nuclei

What would happen if mitosis happened without cytokineses? - Cells would have multiple nuclei

How do prokaryotic cells divide? - binary fission

Structure of a chromosome - consists of two sister chromatids and a centromere

How many chromosomes are in a human skin cell? - 46 (23 pairs = 23x2=46)

How many chromosomes are in this picture - 6

How many chromosomes are in this picture? - 6

Phases of mitosis in order