Download Control of the Cell Cycle Division VS Differentiation • Development

Control of the Cell Cycle
Division VS Differentiation
• Development of Multicellular Organisms
- A fertilized __egg__ ( __one__ __cell__ ) gives rise to a large number of __identical__
cells through __cell_ ___division__
- As development continues, cells ___increase__ in __number__ BUT also go through
__cell___ ___differrentiation___
Cell Differentiation– when cells become __specialized__ in
__structure____ and ___function__
*How various cell types ( _blood, muscle, skin cells_) are organized:
__Cells__  ____Tissues___  ___Organs__  ____Organ Systems___
Stem Cells -
__unspecialized __ cells that have the ability to ___differentiate__ into
one or more types of specialized cells
Examples 1.) ___Embryonic Stem Cells____
2.)____Adult Stem Cells (found in bone marrow)______________
Control of Cell Division– the cell cycle is driven by a ___chemical control system_____
• Internal ( __enzymes__) and external ( ___environment__) signals help to __control___
the cell cycle
• ___Checkpoints___ are also in place to ___regulate___ the cell cycle
• __Stop_ and __Start__ signals keep the cell “___cycling____” correctly
Uncontrolled cell Division–
sometimes cells do NOT respond to the body’s control system and
___divide___ __excessively__
Cancer – a single cell is transformed into a __cancer__ __cell__ ( do not obey the control systems)
• Normally the bodies __immune__ system will recognize that the cell is damaged and __destroy__ it
• But if it ___evades__ destruction, the cancer cell will continue to __divide__and each daughter cell will be cancerous
• A mass of cancer cells is called a ___tumor____
Malignant Tumor – mass of cells that __invades__ / ___impairs__ the functions of one or more organs
Benign Tumor – mass of abnormal cells that remain at the ____original site___ (do not spread)
- “noncancerous”