6.2 Mitosis Flashcards
What is mitosis?
process by which NUCLEUS DIVIDES
What are the stages of mitosis?
prophase metaphase anaphase telophase
What happens during prophase?
chromosomes CONDENSE
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NUCLEOLUS disappears + NUCLEAR ENVELOPE begins breaking down
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CENTRIOLES migrate to opposite poles, SPINDLE FIBRES form + ATTACH to centromeres.
￬
NUCLEAR ENVELOPE disintegrated.
What happens during metaphase?
SPINDLE FIBRES line up chromosomes at EQUATOR (metaphase plate)
What happens during anaphase in mitosis?
centromeres DIVIDE
spindle fibres CONTRACT»_space; SISTER CHROMATIDS pulled to OPPOSITE sides
What happens during telophase?
nuclear envelope + nucleolus REFORM
chromosomes DECONDENSE
Why do chromosomes condense?
prevent entangling
What characteristic feature can be seen under a microscope during anaphase?
V SHAPE formed by chromatids pulled by their centromeres
What is a centromere?
region where 2 chromatids held together
What is mitosis used for?
Growth Repair Replacement
Asexual reproduction
What is the product of mitosis? (after cytokinesis)
2 GENETICALLY IDENTICAL
DAUGHTER cells
What happens during cytokinesis of an animal cell?
CYTOSKELETON pulls plasma membrane inwards >. cleavage furrow
Plasma membrane FUSES with itself»_space; 2 genetically identical daughter cells
Why can plant cells not form a cleavage furrow?
rigidity of cellulose cell wall
What happens during cytokinesis of a plant cell?
VESICLES containing CELLULOSE produced by golgi
line up @ EQUATOR
FUSE with each other (+ plasma membrane)»_space; CELL PLATE
Cellulose cell wall forms along new section of plasma membrane
Why is it important that the plasma membrane forms before the cell wall during cytokinesis of a plant cell?
Cell wall is fully permeable,
so without complete plasma membrane, water would move into cell by osmosis + cause CYTOLYSIS
