Stages of mitosis Flashcards
What happens inside the nucleus in prophase?
chromatin fibres begin to coil and condense to form chromosomes, that will take up stain more intensely
nucleolus disappear
nuclear envelope begins to break down
What happens outside of the nucleus in prophase?
protein microtubules form spindle-shaped structures linking the poles of the cells, these are necessary to move chromosomes in there correct position
in animal cells and some plant cells, two centrioles divides and migrate to opposite poles of the cell, help formation of spindle
What happens in metaphase?
spindle fibres attach to specific areas on the centromeres and move chromosomes to the metaphase plate (equator)
What happens in anaphase?
the centromeres holding the pair of chromatids together divide
the chromatids are separtated
spindle fibres contract and pulls chromatids to poles of the cell
identical chromatids at either pole
forms V shape is the result of them being dragged by their centromeres
What happens in telophase?
chromatids reach the poles and are now called chromosomes
the two sets of new chromosome assemble and the nuclear envelope reforms around them
the chromosomes start to uncoil and the nucleolus is formed
How does cytokinesis occur in animal cells?
cleavage furrow forms around the middle of the cell
the cell surface membrane is pulled inward by the cytoskeleton until is is close enough to fuse around the middle
How does mitosis occur in plant cells?
plant cells have cell walls so it is not possible for a clevage furrow to be formed
vesicles from the golgi apparatus beigin to assemble in the same place as where the metaphase plate was formed
the vesicles fuse with each other and cell surface membrane, dividing the cell into two
new sections of cell wall then form along the new sections of membrane
What would happen if the dividing cell wall were formed before the daughter cells separated?
they would undergo osmotic lysis from the surrounding water
