Cell cycle & mitosis; Meiosis (Chapter 11, 12) Flashcards
_____________ are nuclear units of genetic info & associated proteins
Chromosomes
Describe sister chromatids
- same as parent chromosome
paired threads - held together until mitosis separates them
- genetic info
What are the essential components of the cell theory
living things are made from cells
cells come from other cells
What happens in the interphase portion of mitotic cell division
non dividing cell phase
G1 Phase - makes organelles
S Phase - replication of DNA
G2 Phase - more organelles
define somatic cells
non-gamete cells
copying and dividing
genetic clone
What are the five phases of the M Phase
Prophase
Prometaphases
Metaphase
Anaphase
Telophase
What is the function of mitosis
Growth
wound repair
sexual reporduction
______________ is a copy of one strand of DNA
Chromatid
___________________ is the centre point between the sister chrmatids that bind them together
centromere
________ are the proteins at the centromere where microtubules bind
Kinetochore
____________ the protein ring that stabilizes the loops of the Chromosomes, condeses it
Condensins
What are the two purposes of the microtubules during mitosis
- to adhere to the centromere
- for pulling the diving cells to opposite poles
What protein is responsible for binding down the loops of the sister chromatids together at the centramere
cohesins
______________ is the structure on sister chromatids where mirotubles attach
kinetochore
What is the root for the word meiosis
Lessening act
Becauuse the sperm and egg cells have only 2 chromosomes, whereas all other cells have 4
What is the difference between an allele and a gene
allele is different versons of the same gene -> traits
homologs carry same genes but different traits
What are the four phases of the cell cycle
M-Phase - Cell Division
G1 - Organelles replicated
S Phase: synthesis phase - replication of DNA
G2 - more organelles replicated
Meiosis leads to ________ cells
Somatic or gamete
gamete
What are the 3 key events mitosis is responsible for
- growth
- wound repair
- reporductive (asexual)
What is the root of the word cytokenesis
cell movement
Put the 5 phases of mitosis in order
- metaphase
- telophase
- prometaphase
- prophase
- anaphase
Prophase
Prometaphase
metaphase
anaphase
telophase
______________ are non gamete cells, coying and dividing - a genetic clone
somatic cells
When during M phase are the chromosomes the smallest
Prophase
Describe what is going on to the chromosome during prophase
before Phase
chromosome compaction
spindle app, working on the structure
cytoplasmic creation
Describe what is going on during prometaphase
before middle phase
nuclear envelope dissapears
spindle enters nuclear area
microtubules attach to chromosomes on the kinetechares of each chromosome
some of the microtubules overlap - for cell division mobility
What is happening with the chromosomes during metaphase
the are being lined up at the midpoint
the formation of the spindle apparatus is complete
What is happening during the anaphase
against phase
sister chromatids separate and move to opp poles
spindle app pulls chromosomes and pushes poles of cells away
What is happening during telophase
end phase
nuclear envelop re forms
spindle app disintigrates
describe how the cleavage furrow is happening
via motor proteins actin and myosin
part of cytokinesis
Microtubules - how do they work on the chromosomes and cell division
microtubles attach to the kinetochore on it`s positive side, which is also where it lengthens and sortens to pull the chromosome in place
microtubules also overlap and their function is cytokinesis
what are the two distince proteins in Mitosis Promoting Factor MPF
Kinase
cyclins
What is the purpose of MPF
induces mitosis
Which of the proteins in MPF fluctuate in concentration of the cell cycle
cyclin bound to cyclin dependend kinase CdK
Which phase are cyclines at theeir highest concentration
m phase
What does the kinase do
enzyme cleives Pi from ATP on target protein therefore a regulatory element
Whoe does the MPF work with the cyclins and >CdK (cyclin dependant Kinase)
On the CdK the are 2 phophoralated sites which is the MPF in it`s inactive state
Late in G2 phase enzyme cleaive on Pi and preomes active -> M phase
How is MPF deactivated
during anaphase it starts to degregate
cyclin gets marked for destruction by ubiqutin and the proteasome
therefore concentration degredated and concentrations reduce
Where in the cell cycle are the checkpoints
G1 - Is it big enough, enough nutrients, social signals for growth, is the damage to the DNA,
G2 - MPF key in signaling, if error in DNA the dephoporalization fo MPF is blocked
Metaphase checkpoint - pass go if chromosomes attached to spindle app correctly
what is the definition of apoptosis
cell self destruction
During the G1 checkpoint if _________ defective DNA remains unrepaired, this protein is also called
p53
tumor supressors
Cancer arrises from faulty checkpoints, there are two major types. What are they
Make proteins for cell growht active when they shouldn`t
defects prevent tumor suppressor cells from shutting down during the cycle
what does platelet derived growth factor PDGF do
it is a growth factor
binds to tyrosine kinases on cell mb
