Cell Cycle Flashcards
Composition structure of a chromosome
Chromatin- 40% DNA, 60% Protein
Chromosome- 1 long strand of DNA
Compaction structure of a chromosome
DNA, nucleosome, solenoid, rosettes, and a chromosome
double helix
DNA
DNA wrapped around histone protein
nucleosome
nucleosomes in a spiral
solenoid
flower arrangement of soleniods
rosettes
diploid
w/ pairs (2n)
haploid
w/o pairs (n)
one from each parent
homologous chromosomes
DNA is duplicated on a chromosome
sister chromatids
prophase prometaphase metaphase anaphase telophase
phases of the cell cycle
interphase
preparing for mitosis
after S phase (DNA replication) two sister chromatids
in G2, centrioles replicate (organize microtubles)
end G2, chromosomes begin to condense
G1/S checkpoint
decision to divide
G2/M checkpoint
DNA synthesis a success, committment to mitosis
spindle checkpoint
make sure chromosomes are attached to spindles
what controls checkpoints
internal-cyclins, external-growth factors
failure to control checkpoints
cancer
normal: prevent damaged cells from dividing
cancer: turned off
i. e. cutting the brakes on a car
tumor suppressor
normal: growth factor signals
cancer: turned on permantely
i. e. gas pedal sticks to the floor
proto-oncogenes
outer of the centromere
kinetochores
centrioles
divided and organizes spindle fibers during mitosis and meiosis
gain or loss of chromosomes
aneuploidy
chromosomes to do not separately properly in mitosis
nondisjunction
3 copies of a chromosome
trisomy
1 copy of a chromosome
monosomy
pataus syndrome
cleft palette
polydactyly
trisomy 13
downs syndrome
1/750 children
short stature, mental capacity varies
trisomy 21
