In mitosis, the process through which one cell divides into two daughter cells, the main difference between open and closed mitosis is how the chromosomes are segregated. In open mitosis, the nuclear envelope breaks down before chromosome segregation, while in closed mitosis, the nuclear envelope remains intact during the process.
Key Takeaways
- Open mitosis involves the breakdown of the nuclear envelope before chromosome segregation.
- Closed mitosis maintains the nuclear envelope’s integrity during chromosome segregation.
- Open mitosis mainly occurs in higher-level eukaryotes, while closed mitosis is more common in lower eukaryotes like fungi.
What is Open Mitosis?
Open mitosis is a type of cell division where the nuclear envelope breaks down before chromosomes are segregated. During this process, the nuclear membrane and nuclear pore complexes disassemble, causing nuclear proteins and cytoplasmic proteins to mix together. The mitotic spindle then elongates and captures the kinetochores. Open mitosis can be observed in animals, plants, and certain eukaryotic supergroups, but not in Excavates.
What is Closed Mitosis?
Closed mitosis is a type of cell division in which the nuclear envelope remains intact during the segregation of chromosomes. In this process, the spindle forms without the nuclear envelope breaking down. Closed mitosis is common in fungi and occurs within six eukaryotic supergroups, including Excavates, which only undergo closed mitosis. Closed mitosis is considered the most ancient mechanism of eukaryotic cell division and is important for maintaining nuclear envelope integrity.
What are the Similarities Between Open and Closed Mitosis?
Both open and closed mitosis are mechanisms of cell division in eukaryotes that involve the nuclear envelope. In both types, the mitotic spindle generally segregates chromatids during mitosis.
What is the Difference Between Open and Closed Mitosis?
The key difference between open and closed mitosis is how chromosomes are segregated. In open mitosis, the nuclear envelope breaks down before chromosome segregation, while in closed mitosis, the nuclear envelope remains intact. Open mitosis mainly occurs in multicellular higher-level eukaryotes, whereas closed mitosis is more common in lower eukaryotes like fungi.
Summary – Open vs Closed Mitosis
Open and closed mitosis are two mechanisms of cell division where chromatids are generally segregated by the mitotic spindle during mitosis. The main distinction between the two lies in the integrity of the nuclear envelope during chromosome segregation. Open mitosis involves the breakdown of the nuclear envelope, while closed mitosis maintains envelope integrity. Open mitosis is more common in higher-level eukaryotes, while closed mitosis is primarily found in lower eukaryotes such as fungi.
