Which of the following is not a part of mitosis?

In mitosis,karyokinesis is usually followed by cytokinesis,but this is not always the case. If a cell undergoes mitosis but cytokinesis does not occur,what is the result?

In the given figure, what does the part labeled "$R$" represent?

In animal cells,cytokinesis is initiated by which process?

What does the following figure represent?

Which of the following structures is the base for defining the formation site of the cell plate at the end of nuclear division?