The Cell Cycle and Mitosis Regulation

The Key Roles of Cell Division Cell division functions in _________________________________ Unicellular organisms (ex. Amoeba) will divide to reproduce entire organisms Cell division also will allows a multicellular organism to ______________________

The Key Roles of Cell Division DNA is passed from one generation of cells to the next without dilution. -____________________ - moves the 2 copies to opposite ends of the cell - ______________________

Cell Division distributes identical sets of chromosomes to daughter cells A cell’s genetic material is called its ________________ - prokaryote = ____________________ - eukaryote = number of DNA molecules

- the nuclei in human __________contains 23 chromosomes The replication and distribution of DNA is manageable because it is packaged into chromosomes - the nuclei in human ________________contain 46 chromosomes (23 pairs) - the nuclei in human __________contains 23 chromosomes 2 chromosomes 1 chromosome 2 chromatids

Organizing DNA DNA is organized in _____________ ACTGGTCAGGCAATGTC DNA DNA is organized in _____________ double helix DNA molecule wrapped around histone proteins like thread on spools DNA-protein complex = ______________ organized into long thin fiber ____________________________________________ histones chromatin double stranded chromosome duplicated mitotic chromosome

Cell cycle Cell has a “life cycle” cell is formed from a mitotic division cell grows & matures to divide again cell grows & matures to never divide again ____________ liver cells G1G0 epithelial cells, blood cells, stem cells brain / nerve cells muscle cells

The cell cycle is driven by specific chemical signals present in the cytoplasm Sequential events of the cell cycle are directed by a distinct cell cycle control system - _____________________ - the cell cycle is regulated at certain checkpoints by internal and external controls

The checkpoint is a control point where stop and go-ahead signals can regulate the cycle - kinases, a type of regulatory protein that activate or inactivate other proteins, give the signals for G1 and G2 checkpoints

To be active the kinase must be attached to a cyclin (kinases become cyclin-dependent kinases or Cdks) - _____________________________________________________________ - first called MPF = “maturation promoting factor” or “M-phase-promoting factor”

- ____________________________________________________________________ Internal and external cues help regulate the cell cycle - for cells to divide a growth factor, a specific protein, is released to stimulate cell division

The discovery of growth factors has led us to understand ______________________________of cell division - when a cell population reaches a certain density, the amount of growth factors and nutrients needed for division becomes insufficient for increased growth

Most animal cells also exhibit _____________________________________________ - to divide, the cell must be attached to a substratum (ex. inside of a culture jar or extracellular matrix of a tissue)

Cancer cells have escaped from cell cycle controls - ______________________________________________ - they do not stop dividing when growth factors are depleted; don’t respond to ________________________

- if cancer cells stop dividing, it is at random points and not at the checkpoints Cancer begins when a single cell tissue undergoes a __________________ - if the cell evades destruction by the immune system it may form a tumor

- if the abnormal cell remain at the original site, it is called a _____________ - a ________________becomes invasive enough to impair the functions of organs - the spread of cancer cells from the original site is called ___________