Chapter 9 Flashcards
Chromatin
The complex of DNA and proteins that makes up eukaryotic chromosomes
Mitosis
Cytokinesis
Division of genetic material in nucleus
Division of cytoplasm: ring of microfilaments squeeze cell into two.
Interphase
Where call is not dividing
G1: growth phase, produces cellular components
S phase: synthesis: DNA is replicated
G2- second gap phase, growing and preparing for division
Mitotic spindle
An assemblage of microtubules and associated proteins that is involved in the movement of chromosomes during mitosis. (Forms during prophase)
Kinetochore
Structure made up of proteins that have assembled on specific sections of chromosomal DNA at each centromere.
Nonkinetochore microtubules
Responsible for elongating the whole cell during anaphase
Cell plate
A membrane-bounded, flattened sac located at the mid line of a diving plant cell. Made from vesicles made in Golgi.
Binary fission
Prokaryotic division where cells grow 2x the size and the divide into two.
Origin of replication
Site where the replication of a DNA molecule begins, consisting of a specific sequence of nucleotides.
Cell cycle control system
Cyclically operating set of molecules in the cell that both trigger and co ordinates key events in the cell cycle.
- built in clock
- regulated by check points
Checkpoints
Control point in cell cycle where stop and go signals can regulate the cycle.
Where are the three important checkpoints
G1, G2, and M phase
G1- divide or no
G2- Free of mutation after replication of DNA
M-All kinetochores attached to microtubules
Restriction point
Most important, if given go ahead the cycle starts if not it goes into G0 phase= non dividing.
Growth factor
Protein released by certain cells that stimulates other cells to divide
Density dependent inhibition
A phenomenon in which crowded cells stop dividing.
