Bio12.4 Flashcards
Prokaryotes evolved ____ eukaryotes
Before
How did mitosis evolve
Binary Fission
Certain protists exhibit types of __ ___ that seem intermediate between binary fission and mitosis
Cell division
How is the cell cycle regulated?
Molecular control system
The cell cycle appears to be driven by specific ____ ___ present in cytoplasm
Chemical signals
What is evidence of the cell cycle control system?
Cultures mammalian cells at different phases of the cell cycle fused to form a single cell with two nuclei
Checkpoints
Where the cell cycle stops until a go-ahead signal is received
Name the checkpoints
G1,G2, M
Cyclins and cyclin-dependent kinases (CdKs)
Two types of regulatory proteins involved in the cell cycle control
MPF-stand for
Maturation-promoting factor
MPF
A cyclin-Cdk complex that triggers a cell’s passage past the G2 checkpoint into M phase
Many signals registers at checkpoints come from ____ _____ mechanisms within the cell.
Cellular surveillance
What is the most important checkpoint in animal cells. Why?
G1; receives go-ahead to complete S, G2, M and divide
What happens if the go-ahead from G1 is not received?
G0 phase; nondividing state
