Plant Cells

• After anaphase, carbohydrate-rich vesicles form in a row at the centre of the cell (equatorial plane)
  

• The vesicles fuse together and an early cell plate begins to form within the middle of the cell
  

• The cell plate extends outwards and fuses with the cell wall, dividing the cell into two distinct daughter cells

• Because this separation originates in the centre and moves laterally, it is described as centrifugal
  

In most cases, cytoplasmic division results in two cells of comparable sizes, with all organelles equally segregated between the daughter cells

• Some organelles (including endoplasmic reticulum and Golgi bodies) are disassembled during nuclear division and then redistributed and reformed in daughter cells

• Other organelles (including the mitochondria and chloroplast) undergo their own division process prior to cytokinesis to ensure the daughter cells have adequate quantities

• Any daughter cell that does not possess a full complement of organelles will be unable to maintain the functions of life

Some cells do not partition their cytoplasm equally when they divide – instead the parent cell retains its physical identity and a new cell evolves as an outgrowth

• This type of unequal cytokinesis can occur in both unicellular organisms (e.g. budding in yeast) and multicellular organisms (e.g. oogenesis in humans)

Budding

• Budding is an asexual reproduction method employed by a range of organisms, including unicellular yeast

• The division of cytoplasm is asymmetrical – the daughter cell receives only a fraction of the cytoplasm from the parent cell

• Initially the daughter cell will remain attached to the parental cell as an outgrowth, before eventually separating and developing into an independent structure 

Oogenesis

• Oogenesis is the process by which human egg cells (ova) are produced following meiotic division in females

• During oogenesis, the cytoplasm and organelles are retained by a single cell, with the remainder forming a smaller polar body that will typically disintegrate

• Retaining the cytoplasm and organelles within a single cell ensures that a fertilised ovum has sufficient resources to undergo embryonic development

Unequal Cytokinesis