6. The cell cycle Flashcards
genome
cell’s genetic information/cell’s DNA
what does chromatin consist of?
the entire complex of DNA + proteins building chromosomes
which protein attaches two sister chromatids together?
cohesins
which phase is the most variable in length?
G1
the 5 phases of mitosis
prophase
prometaphase
metaphase
anaphase
telophase
in which phase does the mitotic spindle begin to form in the cytoplasm?
during Prophase
during which phase do the spindle microtubules start to attach to the 2 kinetochores of the chromosome?
during Prometaphase
CLEAVAGE process
cytokinesis in animal cells
how does cytokinesis happen?
due to the interaction of actin microfilaments with myosin molecules
which organisms undergo binary fission?
- prokaryotes= bacteria and archaea
-single-celled eukaryotes= amoeba
the difference of binary fission in prokaryotes and eukaryotes
in eukaryotes (amoeba) binary fission includes mitosis
which are the regulatory molecules of the cell cycle control?
- protein kinases
-cyclins
the condition of protein kinases to be in their active form
they must be attached to a cyclin
CDKs
cyclin-dependent kinases
what happens to the cyclin rate during the S and G2 phases?
it rises rapidly
what happens to the cyclin rate during the M phase?
it goes down
MPF
maturation-promoting factor or
M-phase promoting factor
the role of MPF
triggers the cell passage to the M phase
what happens to MPF during anaphase?
it initiates that destroys cyclin and inactivates CDK (the non-cyclin part of the MPF)
the two types of cancer are
- Benign tumor
- Malignant tumor
Benign tumor
when abnormal cells do not spread to other tissues
does not cause serious problems, it is removed surgically
metastasis
spread of tumor cells to other sites of other tissues
which is the longest phase of mitosis?
prophase
what differs between two homologous chromosomes?
alleles
what kind of reproduction do yeast cells undergo?
asexual
do genetic differences occur during asexual reproduction?
yes
what kind of reproduction do fungi and protists undergo?
sexual
Leptotene
1st phase of prophase 1
chromosomes start to condense, homologous ch. start to condense
Zygotene
2nd phase of Prophase 1
homologous chromosomes align together in synapsis. the paired ch. are called bivalents/tetrads
Pachytene
3rd phase of prophase 1
crossing over happens
diplotene
5th phase of prophase 1
homologous ch. separate, but remain attached at points called CHIASMATA
DIAKINESIS
last phase of prophase 1
nuclear membrane begins to break down
