![]() Only homologous chromosomes can perform this. Since this stage is all the about restructuring of the chromosomes and recombination. This stage and phase employ the use of homologous chromosomes. This phase of meiosis I stage differs from the second prophase in terms of the types of the chromosomes used. Instead of a crossover, it’s the two pairs separating into two centrosomes. Thus, there is no DNA crossover that can be identified at this stage. It is worth noting here that instead of the chromosomal cells crossover, in prophase II, the existing is actually replicating and not combining. The process finally leads to a total or complete synapse thus enabling the next stage to take place. The combining chromosomes are hereditary and thus not identical. The crossover brings about mainly a change in genetic composition through recombination. With the pairing of the homolog chromosomes having taken place, the next move in prophase I is for the chromosomal content to exchange within the pair. Secondly, this stage involves replication over pairing. Firstly, this stage does not involve the use of homolog chromosomes. Prophase IIĭifferent from prophase I, this point of Meiosis does not involve any pairing of homologous chromosomes. The homolog pair now completely synapse gradually to a point of no distinction. There follow changes that come with meiosis processes. Here, two members of the homolog pair simply referred to as bivalents come together and form a pair at this stage. You should note that the homologs enter meiosis unpaired. This is the only site and point where the pairing of homologous chromosomes happens. It happens immediately without passing through the interphase. Totally different from prophase I, prophase II does not require an interphase. As for duplication, it has already happened in interphase. ![]() What happens in prophase I is only pairing of the homologous chromosomes and later crossover of its genetic content. The interphase is a long process and it occurs immediately before meiosis I. However, this is the most important phase as the cell performs the most vital duty of ensuring the division carries a similar copy of the original. An interphase refers to a stage at which no cell division takes place. The duplication of the chromosomes occurs in the interphase. Prophase II is the first stage of meiosis II. On the other hand, the stage of meiosis II involves the formation of a daughter centriole from the original and separation of the same. It is at meiosis I that the cell becomes visible.Īll this happens in prophase I of meiosis I. meiosis I is the center of cell duplication and visibility. Meiosis I is known, to begin with an interphase after which prophase I comes in. After a very long latent period in interphase, the developments continue next in prophase I. Prophase I is simply the first stage in Meiosis I. Prophase I begin and take place at the initial stage of Meiosis I whereas Prophase II begins in meiosis II. Difference between the inception of prophase I and II It is characterized by a lot of latency and maturity. Interphase is the phase between meiotic stages. Interphase therefore refers to a phase between other phases of a stage. Inter originates from Latin just like a pro. Prophase, therefore, refers to an initial phase of a stage like in meiosis. A new plane is formed and is around 90 degrees to the original spindle in Meiosis I.Īs is commonly known, pro originates from Latin and means before. At its advanced stage, the nuclear envelope breaks. The two pairs separate and form two centrosomes. A daughter centriole forms and places itself perpendicular to the ‘mother’. Only replication of centrioles takes place. It occurs immediately without passing through an interphase. Prophase II is the first stage of Meiosis II. It is at this stage that nuclei and the nuclear envelope disappear thereby allowing for the spindle nuclei to enter the nucleus. The paired chromosomes now form bivalents. Genetic recombination occurs at this stage because it is where crossover mainly does occur. At this point, the chromosomes gain visibility by thickening and shortening. It involves the pairing and crossovers of the already duplicated chromosomes. Difference between the definitions of Prophase I and II
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