cell and nuclear division basics Flashcards
interphase: G1
cells grow and prepare for division
interphase: S
synthesis: dna replication in nucleus
Interphase: G2
cells are still growing and preparing
what stages are in the M phase
- mitosis/meiosis 2. Cytokinesis
prokaryotic vs. eukaryotic when dividing
eukaryotic=cell divison. prokaryotic=no cell division, uses binary fission
what happens to chromatins when and after dividing
chromatins condensed->chromosome. then uncondenses afer division
why do chromatins condense
chromsomes=condensed->good for cell division
why do chromosomes decondense
chromatins=uncondensed->easy for cellular machine to read.
what phase do chromosomes have 2 identical molecules/sister chromatids
S phase
what protein allows the chromsomes to move along the cell
spindlefibres (made up of microtubles)
M phase: prophase
chromosomes condense, nucleus dissolves, paired chromatids move to opposite poles
M phase: metaphase
spindle fibres connect centrosomes to each pair of chromatids to move chromatids to middle
M phase: anaphase
Spindle fibres shorten and separate sister chromatids, moving them to the opposite poles. seperated chromatids are chromosomes
M phase: telophase
chromosome decondense, nuclei reforms around 2 diff chromosome sets
M phase: cytokinesis
divides the parent cell into two daughter (usually equal) by spliting cytoplasm and nucleus
M phase: cytokinesis in animals
division=centripetal. in-tucking plasma membrane at the middle. then protein will make a ring to split.
M phase: cytokinesis in plants
division=centrifugal. vesicles formed by golgi apparatus (Cell organelle) that fuse to make cell walls and plasma membranes in the equator/cell plate to divide the two cells.
when a mother cell splits, what is the result?
two daughter cells (that can be identical or varied cells)
why is oogenesis
egg production in humans
steps of oogensis and why it is an unequal divison of cytoplasm
primary oocyte (immatureegg cell) dividese into a small polar body and a secondary oocyte. secondary oocyte froms an ovum and another polar body. polar body 1 forms two other tiny polar bodys.
what happens to the tiny polar bodies
degenerate, cytoplasm and celluar contents are given to the ovum.
why is the ovum helpful
provides nutrients + energy for growing embryo.
why is nuclear division (mitosis or meiosis) important
so both daughter cells will have a nucleus when the cell splits
what is the difference of meiosis and mitosis in terms of chromosomes
mitosis has the same # of chromosomes as the parent cell/two set (2n or diploid) but meiosis has half the chromsomes of the parent cell/one set(n or haploid)
