Chapter 12 The Cell Cycle Flashcards
how do cells replicate
- copy chromosome, separate copies, divide the cytoplasm to generate daughter cells that have the same chromosomal complement to the parent cell
how do eukaryotic cells divide
the cells cycle through interphase and M phase
what happens during interphase
S (synthesis) Phase: chromosomes replicate
G1 and G2 Phases: cells grow and prepare for division
what happens during M phase
mitosis or meiosis, when chromosome separate, and the parent cell divides
Prophase
chromosomes condense, spindle apparatus begins to form, polar microtubule over lap each other
Prometaphase
nuclear envelope my dissolve, microtubules attach to the kinetochores of the chromosomes, which begin moving to the beginning of the spindle
Metaphase
All the chromosomes are positioned in the middle of the spindle, the spindle is anchored to the plasma membrane by astral microtubules
Anaphase
Sister chromatids are pulled apart by the disassembly of the kinetochore micro tubules at the kinetochore. The separated chromatids are now daughter chromatids. the spindle poles disintegrate at the positive end to further separate the replicated chromosomes
Telophase
daughter chromosomes are fully separated and are clustered at opposite poles of the spindle. A nuclear envelope forms around each set and the chromosome decondense
cancer
general term for a disease resulting from cells dividing in an uncontrolled fashion
cleavage furrow
where cytokinesis begins in eukaryotic cells
binary fission
how bacterial cells divide
M phase promoting factor
MPF induces M phase in all eukaryotes, made up of kinase and cyclins
kinase
an enzyme that catalyzes the transfer of a phosphate groups, the cyclin dependent kinase is a subunit of the MPF
cyclins
family of proteins whose concentrations fluctuate throughout the cell cycle. cyclin concentrations build during interphase and peak during M phase
G1 checkpoints
pass if: cell size is adequate nutrients are sufficient social signals are present DNA is undamaged
G2 checkpoint
pass if
chromosomes have replicated successfully
DNA is undamaged
activated MPF is present
M Phase checkpoints
Pass if
chromosomes have attached to spindle apparatus
chromosomes have properly segregated and MPF is absent
negative feedback
when a process is slowed or stopped by one of its products
tumor
formed by cells that keep dividing due to issues with cell cycle checkpoints
chromosome
a structure containing genetic information in the form of genes
chromatin
the material tht makes up the eukaryotic chromosomes, consists of a DNA molecule complexed with histone proteins
Chromatid
one double stranded DNA copy of a replicated chromosome with its associated proteins
Sister chromatids
the 2 attached, double stranded DNA copies of a replicated chromosome, When chromosomes are replicated, they consist of two replicated chromosomes, the genetic material in the sister is identical, whe they separate during mitosis, they become independent chromosomes
Centromere
a specialized region of a chromosome where sister chromatids are most closely joined to each other
microtubule organizing center
any structure that organizes microtubules
centrosome
the microtubule organizing center in animals and certain type of plants and fungi
centrioles
cylindrical structures consisting of microtubule triplets, located inside animal centrosomes
spindle apparratus
structure that produces mechanical forces that move replicated chromosomes during early mitosis and pull chromatids apart in late mitosis
cell division
the splitting of preexisting cells
embryos
newly developing organisms confirmed cell division
meiosis
leads to production of sperma nd eggs
mitosis
leads to production of ssomatic cells
somatic cells
body cells
