Flashcards in Mitosis Deck (13):
What is mitosis?
-Process of cell division in eukaryotic cells, but mainly nuclear division.
-Ensures both daughter cells produced when parent cell divides are genetically identical.
What is mitosis necessary for?
-When all daughter cells have to be identical so for, growth and repair of tissues.
-Also, for asexual reproduction.
What is a chromosome?
What is a chromatid?
-Two identical DNA molecules.
What happens to chromosomes during interphase?
-Each chromosome is converted into chromatids.
What is the centromere?
-Region where two chromatids are joined together.
What are the four stages of mitosis?
-Prophase, metaphase, anaphase and telophase.
What happens during prophase?
-Chromatin fibres begin to coil and condense to form chromosomes.
-Nucleolus disappears and nuclear membrane breaks down.
-Spindle fibres link the poles of the cell.
-Two centrioles migrate to opposite poles.
-Spindle fibres attach to centromeres and move chromosomes to centre of cell.
-By the end, nuclear envelope had disappeared.
What happens during metaphase?
-Chromosomes moved by spindle fibres to form a metaphase plate in the centre and held in position.
What happens during anaphase?
-Sister chromatids separated and pulled to opposite poles.
-4 "V" shaped chromatids at each pole.
What happens during telophase?
-Chromatids have reached poles and now called chromosomes.
-Two new sets of chromosomes assemble at each pole and nuclear envelope reforms.
-Chromosomes uncoil and nucleolus forms.
How is cytokinesis performed in animal cells?
-Cleavage furrow forms around middle of cell.
-Csm pulled inwards by cytoskeleton until close enough to fuse.
-Forms two identical daughter cells.