Last Updated on March 19, 2022 by QCity Editorial Stuff
The first major difference between prophase I and prophase II is that in Prophase I, the chromosomes are condensed into visible threads called chromatids. In Prophase II, they become long thin rods (called telophase). The second major difference is that during the first phase of mitosis, spindle fibers form a network around each pair of sister chromatids to pull them apart from one another. This process continues until all four pairs have been separated due to forces exerted by microtubules. Whereas during prophase II, this has already occurred so no part of the cell moves or changes shape before metaphase begins.
In the first phase of meiosis, prophase I, an individual’s chromosomes condense and become visible. In prophase ii, which occurs after DNA synthesis has occurred and before metaphase I, the cell becomes divided into two cells by a cleavage furrow. The result is that each chromosome has been duplicated to create two identical sets. Prophase ii also marks the final stage in the nuclear division before mitosis. Thus far we have seen four stages: interkinesis (a resting period), prophase 1-4 (nuclear division). We will now move onto metaphase I where sister chromatids are pulled towards opposite poles – this process is called spindle formation or bipolarity.
Comparison between Prophase I and Prophase ii
|Parameters of Comparison||Prophase I||Prophase ii|
|Definition||Prophase i is the first phase of mitosis, which is when the nuclear envelope breaks down.||Prophase ii includes metaphase and anaphase|
|Chromosomes||In prophase I, the chromosomes have not yet replicated themselves||Prophase II is when the chromosomes have replicated themselves and they become visible to a microscope|
|Meiosis||Prophase I is the first stage of meiosis, and it is also called the leptotene phase||Prophase II is the second stage of meiosis, and it is also called zygotene|
|Pairs||In prophase I, each chromosome has 4 pairs of sister chromatids (two copies per chromosome||In propointe II there are two copies per chromosome – one copy from each pair of sister chromatids that was present during meiosis 1|
|Nuclear||In prophase I, the nuclear membrane breaks down||n prophase II, there are two new nuclei formed in each cell|
What is Prophase I?
Prophase i is the first stage of mitosis, which is a type of cell division. This process includes two main events: Chromatin condensation and nuclear envelope breakdown. These events are necessary to make way for later stages in mitosis. Prophase I occurs before the metaphase plate forms- this plate separates sister chromatids during metaphase ii to create new daughter cells after cytokinesis has occurred. The prophase I phase takes up 1/4 of the total time that it takes for an individual cell to complete its entire cycle of mitosis.
Prophase I is the first stage of mitosis, and it is responsible for the separation of sister chromatids. This process begins with the formation of the spindle fibers, which then attach to the chromosomes. The chromosomes are then pulled apart by the spindle fibers, resulting in two new daughter cells. Prophase I occurs during Interphase II and typically lasts around 20 minutes. During this time, DNA replication also takes place.
What is Prophase ii?
In prophase ii of meiosis, the chromatids have already started to segregate and the chromosomes are getting shorter. The nuclear envelope has disappeared and the nucleoli are reforming. The spindle fibers start to form and attach to the chromosomes. microtubules from opposite poles of the cell meet at the centromere and pull the chromosome toward them. This separates the sister chromatids, which will eventually become individual chromosomes in daughter cells.
10 Differences Between Prophase I and Prophase ii
1. Prophase i is the first phase of mitosis, which is when the nuclear envelope breaks down.
2. Prophase ii includes metaphase and anaphase.
3. The final stage in prophase ii is telophase.
4. In prophase ii, sister chromatids are pulled apart to opposite ends of the cell’s nucleus.
5. During telophase, chromosomes condense into a single thread-like structure called a metacentric chromosome.
6. Metaphases starts with each chromosome having two sister chromatids that are pulled towards opposite poles by spindle fibers (the centrosomes).
7. Prophase i is where the chromosomes condense and are visible.
8. Prophase ii is when the nuclear envelope breaks down.
9. The spindle fibers form in prophase ii to help with cell division.
10. Chromosomes line up on either side of the equator during metaphase I, but not in prophase ii because they have already condensed into a single X-shaped structure that will be split apart during anaphase i.
Interesting Statistics or Facts of Prophase i
1. Prophase I is the first phase of meiosis, and it is the stage where chromosomes condense into a visible thread.
2. In prophase I, each chromosome consists of two sister chromatids that are tightly coiled together.
3. The process of prophase I end with an event called “synapsis” which involves the pairing up of homologous chromosomes to form a bivalent structure.
4. Anaphase 1 occurs during this time as well, when one member from each pair separates from its other half and moves towards opposite poles on either side of the cell.
5. The result is four daughter cells at different stages in their life cycle – two haploid gametes (spermatozoa or ova) and two diploid cells (mitotic spindles).
6. Cycles repeat for another round until all 4 phases have been completed; then they start over again for another prophase 1.
Interesting Statistics or Facts of Prophase ii
1. Prophase II is the second of four phases in cell division.
2. In prophase II, the chromosomes form a train-like structure called a “synaptonemal complex”.
3. The synaptonemal complex will dissolve when anaphase starts.
4. The process of prophase I and II is also known as meiosis or sexual reproduction.
5. When cells divide by mitosis, they produce genetically identical offspring while when cells divide by meiosis, they produce offspring with half their genetic information from each parent.
6. Meiosis only occurs in gametes (sperm and egg) and not in somatic cells so it does not affect inheritance patterns for traits like hair color or height since these are determined by genes inherited from both parents.
The prophase is the first phase of mitosis and meiosis. Prophase I occurs before the cell starts to divide, while prophase ii happens after it has divided. The main difference between these two phases is that in prophase I there are still chromosomes attached at their centromeres, but in prophase ii they have been pulled apart into chromatids (which allow for replication).
The prophase I phase is the first stage of mitosis. Prophase ii occurs after this and it involves nuclear division. The cells in our body are constantly regenerating themselves, which means that they go through a cycle of cell division to maintain their numbers. For them to divide properly, there must be an exact amount of chromosomes per daughter cell so as not to cause any genetic abnormalities from being passed on from generation to generation within the species. When these two stages occur simultaneously, we have what is called prometaphase-i then prometaphase-ii or M phases respectively where one follows another without interruption because both processes happen at once during metaphase following meiosis I and II. This will result in four new cells.
Resource 01: https://biologydictionary.net/prophase-1/
Resource 02: https://www.biologyonline.com/dictionary/prophase-ii