Cytokinin maintains meristem by controlling cell division

 Deficient mutants – lonely guy (LOG)/STM

 Gene activates cytokinins

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#Unit 4. Cell Communication and Cell Signaling

Cancer cells 

acquire a drive to proliferate 

does not require an external inducing signal

fail to sense signals that restrict cell division

survive when they should die

TLS Online TPP Program

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#Unit 4. Cell Communication and Cell Signaling

Tumors are detected only after they have reached 1cm3 in size.

TLS Online TPP Program

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#Unit 4. Cell Communication and Cell Signaling

Precancerous cells have: 

lost contact inhibition

less adherent and more rounded than normal cells

continue to divide

TLS Online TPP Program

#Id: 10394

#Unit 4. Cell Communication and Cell Signaling

Malignant tumors are classified by their embryonic

tissue of origin:

Carcinomas -derive from epithelia such as endoderm

(gut epithelium) or ectoderm (skin and neural epithelia) 

Sarcomas - derive from mesoderm (muscle, blood, and

connective tissue precursors)

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#Unit 4. Cell Communication and Cell Signaling

Leukemias 

a class of sarcomas, grow as individual cells in the blood

TLS Online TPP Program

#Id: 10396

#Unit 4. Cell Communication and Cell Signaling

Melanoma 

Cancer that develops from the Pigment producing cells of skin