Question

The diagram given alongside shows a stage during mitotic division in an animal cell:

1. Identify the stage. Give a reason to support your answer.
2. Draw a neat labelled diagram of the cell as it would appear in the next stage. Name the stage.
3. In what two ways is mitotic division in an animal cell different from the mitotic division in a plant cell?
4. Name the type of cell division that occurs during:
   1. Growth of a shoot
   2. Formation of pollen grains

Answer 1

1. The stage present in the given diagram is anaphase. The sister chromatids have separated at their centromeres and are moving towards the opposite poles of the cell, pulled by the shortening of the spindle fibres. Additionally, a cleavage furrow is beginning to form at the equator.
2. 
   
3. 
   

   Features	Animal cell mitosis	Plant cell mitosis
   Astrophere/Asters	Asters are formed around centrioles at the poles (Amphiastral).	No asters are formed as centrioles are completely absent (Anastral).
   Cytokinesis method	Cytoplasm divides by the deepening of a cleavage furrow from the outside inward (centripetal).	Cytoplasm divides by the formation of a cell plate starting from the centre outward (centrifugal).

4. 1. Growth of a shoot: Mitosis (occurs in somatic/meristematic tissue for physical growth).
   2. Formation of pollen grains: Meiosis (occurs in reproductive cells to form haploid gametes).