What are the differences between open and closed mitosis?

Question

Accepted Answer

Basis of differentiation

Open mitosis

Closed mitosis

Definition

Open mitosis is the separation of chromosomes subsequent to nuclear envelope breakdown (NEBD)

Closed mitosis is the separation of chromosomes and  spindle formation without NEBD

Occurrence

In multicellular organisms

Occurs in lower eukaryotes (typically in fungi)

Mechanism

The nuclear envelope disintegrates prior to the chromosomes segregating

Chromosome division occurs within the cell nucleus

Significance of evolution

Open mitosis has been altered several times during evolution

Is the oldest mechanism of eukaryotic cell division

Spindle formation

Spindle fibers form within the nucleus

Spindle fibers form outside of the nucleus

Nuclear membrane

The nuclear membrane disintegrates and then re-forms around 2 sets of segregated chromosomes

The nuclear membrane remains intact

Basis of differentiation	Open mitosis	Closed mitosis
Definition	Open mitosis is the separation of chromosomes subsequent to nuclear envelope breakdown (NEBD)	Closed mitosis is the separation of chromosomes and spindle formation without NEBD
Occurrence	In multicellular organisms	Occurs in lower eukaryotes (typically in fungi)
Mechanism	The nuclear envelope disintegrates prior to the chromosomes segregating	Chromosome division occurs within the cell nucleus
Significance of evolution	Open mitosis has been altered several times during evolution	Is the oldest mechanism of eukaryotic cell division
Spindle formation	Spindle fibers form within the nucleus	Spindle fibers form outside of the nucleus
Nuclear membrane	The nuclear membrane disintegrates and then re-forms around 2 sets of segregated chromosomes	The nuclear membrane remains intact