Unit 6:Cell Cycle Flashcards
Mitosis
growth at a cellular level by addition of cells to a population (cell division)
important for reproduction, for growth and for repair purposes
produces daughter cells identical to mother cell
Interphase
G1 Phase
S Phase
G2 Phase
M Phase
Prophase Prometaphase Metaphase Anaphase Telophase
G1 Phase
cell performs regular assigned fxns
maintain homeostasis
will only move to next phase when proper signaling occurs
S Phase
signal to divide reaches the nucleus of cell which results in representation of genome
chromosomes undergo DNA Replication creating sister chromatids
G2 Phase
replication of organelles
cells finish prep to reproduces waiting for signal to go into M phase
Prophase
nuclear envelope dissolved
nuclear membrane material will break down
spindles and asters begin to form
chromatin condenses into chromosomes
sister chromatids aligned
sister chromatids held at centromeres
Prometaphase
nuclear material is condensed
sister chromatids attached by spindles by the kinetochore
sister chromatids begin to move towards the cell plate
Metaphase
chromatids aligned at the center
spindle check point occurs before going into anaphase
Anaphase
chromatids move to opposite poles
Telophase
nuclear envelope reforms
chromatids de condense
aster breaks down
cytokinesis begins
Cytokinesis
cleavage furrow forms in animal cells
cell plate forms in plant cells
two daughter cells are made
Meiosis
makes gametes
diploid germ line cells (2n)
produces haploid germ cells (1n) which mature into gametes
fusion of gametes (fertilization) procedures a diploid zygote
two rounds of Meiosis
one round of cellular material duplication (s phase)
two rounds of karyokinesis and cytokinesis
Prophase 1
when cross over occurs between homologous chromosomes
dissociating linked genes
tetrads gather at synapsis
Metaphase 1
align at the metaphase plate
Anaphase 1
dont break centromere
separate homologous chromosomes
Telophase 1
two daughter cells
Meiosis 2
no s phase between the two m phase rounds
Prophase 2
centrioles replicated
Metaphase 2
align at the metaphase plate
Anaphase 2
separation of sister chromatids
Telophase 2
four daughter cells
First Checkpoint
G1/S Checkpoint
check for cell size, nutrients, growth factors, and DNA damage. If the cell is in good conditions it will then go into the S phase.
Second Checkpoint
G2/M Checkpoint
usage of MPF (mitosis promoting factor)
inactive cdk is activated by a cycling that binds to it then phosphatase is now active which removes a phosphate
Spindle Checkpoint
holds all chromatids in metaphase plate
anaphase promoting complex (APC) triggers anaphase
sister chromatids held together by cohesin
separase breaks down cohesin
securin is an inhibitor of separase
apc marks securin for destruction
