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Chapter 6 Cell Division > Mitosis > Flashcards

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?

-DNA molecule.


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?

-Centromeres divide.
-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.
-Cytokinesis begins.


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.


How is cytokinesis performed in plant cells?

-Vesicles assemble in same place as metaphase plate was.
-Vesicles fuse with each other and cell-surface membrane divides cell into two.
-New cell walls then forms along new section of membrane.