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Chapter 17 key terms

Terms in this set (60)

mitosis
most dramatic stage of cell cycle, (nuclear division) corresponding to the separation of daughter chromosomes
interphase
period of cell cycle between mitoses that include G1, S, and G2 phases
cytokinesis
division of cell following mitosis or meiosis.
M phase
mitotic phase; the phase of the cell cycle that includes mitosis and cytokinesis
G1 phase
(gap 1) that corresponds between mitosis and initiation of DNA replication
S phase
(synthesis) Phase of the cell cycle during which DNA replication occurs.
G2 phase
Gap 2 where cell growth continues and proteins are synthesized in preparation for mitosis.
flow cytometer
Instrument that counts cells in a suspension by measuring the scattering of light by individual cells as they pass by a laser
fluorescence-activated cell sorter
sorts individual cells on the basis of their fluorescence intensity
START
regulatory point in the yeast cell cycle that occurs late in G1. After this point a cell is committed to entering S and undergoing one cell division cycle.
restriction point
A regulatory point in animal cell cycles that occurs late in G1. After this point, a cell is committed to entering S and undergoing one cell division cycle.
cell cycle checkpoints
"checkpoints" where the cell cycle either stops or continues; internal signaling proteins called cyclins regulate whether the cell proceeds to the next stage
DNA damage checkpoints
ensure that damaged DNA is not replicated and passed on to daughter cells
spindle assembly checkpoint
checkpoint that monitors alignment of chromosomes on the metaphase spindle
Maturation Promoting Factor (MPF)
A complex of Cdk1 and cyclin B that promotes entry into the M phase of either mitosis or meiosis
Cdk1
A serine / threonine kinase that is a key regulator of mitosis in eukaryotic cells
cyclins
Member of a family of proteins that regulate the activity of Cdk's and control progression through the cell cycle
Anaphase promoting complex/cyclosome (APC/C)
A ubiquitin ligase that triggers progression from metaphase to anaphase by signaling the degradation of cyclin B and cohesins.
G1 cyclins or Cln's
A yeast cyclin (also called G1 cyclin) that controls passage through START
Cdk's
cyclin-dependent kinases drive progression through different stages of the cell cycle
Cdk inhibitors or CKls
Member of a family of proteins that bind Cdk's and inhibit their activity
Rb
tumor suppressor gene that acts as breaks to slow down cell cycle
tumor suppressor gene
A gene whose protein products inhibit cell division, thereby preventing uncontrolled cell growth (cancer).
E2F
transcription factor which regulates expression of several genes involved in cell cycle progression (can bind with or without Rb)
checkpoint kinases
A protein kinase (Chk1 or Chk2) that brings about cell cycle arrest in response to damaged DNA
ATR
A protein kinase related to ATM that leads to cell cycle arrest in response to DNA damage single-stranded or unreplicated
ATM
a protein kinase that recognizes damaged DNA double-strand break and leads to cell cycle arrest
p53
A transcription factor (encoded by the p53 tumor suppressor gene) that arrests the cell cycle in G1 in response to damaged DNA and is required for apoptosis induced by a variety of stimuli
prophase
The beginning phase of mitosis, marked by the appearance of condensed chromosomes and the development of the mitotic spindle
metaphase
The phase of mitosis during which the chromosomes are aligned on a metaphase plate in the center of the cell
anaphase
The phase of mitosis during which sister chromatids separate and move to opposite poles of the spindle
telophase
The final phase of mitosis, during which the nuclei re-form and chromosomes decondense
centromere
A specialized chromosomal region that connects sister chromatids and attaches them to the mitotic spindle
kinetochore
A specialized structure consisting of proteins attached to a centromere that mediates the attachment and movement of chromosomes along the mitotic spindle
centrosomes
The microtubule-organizing center in animal cells
mitotic spindle
An array of microtubules extending from the spindle poles that is responsible for separating daughter chromosomes during mitosis.
prometaphase
A transition period between prophase and metaphase during which the microtubules of the mitotic spindle attach to the kinetochores and the chromosomes shuffle until they align in the center of the cell
Aurora kinase
A protein kinase family involved in mitotic spindle formation, kinetochore function, and cytokinesis
Polo-like kinase
A protein kinase involved in mitotic spindle formation, kinetochore function, and cytokinesis
condensins
A protein complex that drives metaphase chromosome condensation
cohesins
A protein that maintains the connection between sister chromatids
mitotic checkpoint complex (MCC)
checkpoint complex (MCC)
A complex of proteins that is formed at unattached kinetochores and inhibits progression to anaphase until all chromosomes are aligned on the metaphase spindle
meiosis
The division of diploid cells to haploid progeny, consisting of two sequential rounds of nuclear and cellular division
contractile ring
A structure of actin and myosin II that forms beneath the plasma membrane during mitosis and mediates cytokinesis
leptotene
initial stage of the extended prophase of meiosis I during which homologous chromosomes pair before condensation
zygotene
stage of meiosis I during which homologous chromosomes become closely associated
pachytene
stage of meiosis I during which recombination takes place between homologous chromosomes
diplotene
stage of meiosis I during which homologous chromosomes separate along their length but remain associated at chiasmata
diakinesis
Final stage of prophase of meiosis I during which the chromosomes fully condense and the cell progressed to metaphase
synapsis
the pairing of homologous chromosomes during meiosis
synaptomenal complex
A zipperlike protein structure that forms along the length of paired homologous chromosomes during meiosis.
chiasmata
The X-shaped, microscopically visible region representing homologous chromatids that have exchanged genetic material through crossing over during meiosis.
polar body
A small cell with extremely little cytoplasm that results from the unequal cytoplasmic divsion of the primary (produces the first polar body) and the secondary (produces the second polary body) oocytes during meiosis (oogenesis). The polar bodies degenerate.
cytostatic factor CSF
cytoplasmic factor that arrests oocyte meiosis at metaphase II
Mos
protein kinase that is required for progression from meiosis I to II and for maintenance of metaphase II arrest in vertebrate oocytes
Fertilization
The union of a sperm and an egg
zygote
A fertilized egg
pronuclei
One of the two haploid nuclei in a newly fertilized egg
Ink4
-Cyclin D -- inhibits cdk4 and cdk6
which restriction point in G1
Cip/Kip family
bind to cyclins and inhibit Cdk2 with cyclin A or cyclin E which inhibits entry into S phase
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