So, there is some exchange of genetic material and this process of exchange of genetic material is called crossing over. Now what happens when a couple lie on top of one another? Of course, they will do something (pun intended 😉) and while doing something some material is exchanged in between them. So, this process of pairing of paternal chromosome with maternal chromosome this is called synapses and it is demarcated by presence of synaptonemal complex and because they are pairing with each other we call it Zygotene phase or zygotene stage. This thread-like proteinaceous complex is synaptonemal complex and this process of pairing it is called Synapses. This complex that is formed it is called synaptonemal complex. When they do so a special bond is formed between them and that is not just a bond of love but that is the bond of Proteins.Ī protein complex is formed between paternal chromosome and maternal chromosomes of each homologous Chromosomes pair.
Then, as the love bond in between them becomes stronger, they become close to each other and they pair up with each other, and as they pair up with each other one of them lie on top of the other. In leptotene, condensation of chromatin occur to form chromosomes.
Means thin and we say it lepto because initially the chromatin is thin, and they condense to form Chromosome. And because they are putting heads in lap that is called Leptotene. So, when a love story began to form in couple, they love to put their heads into lap of each other and that is the first phase of love Story. Just think of it that it is a beginning of love story of a beautiful couple, not just a single couple but 23 couples or 23 homologous chromosomes. How you can remember that this is the first phase. So, chromosomes are further supercoiled form of chromatin and their formation demarcates the first stage that is leptotene of prophase one. As the cell division starts, it condenses to form chromosomes. Before prophase starts, genetic material, the DNA, is in the form of thread like structure called chromatin. In the first stage of prophase is like mitosis. Note that there is no demarcation of homologous chromosomes in mitosis. This chromosome pairs are called Homologous chromosomes. They come close to each other and they exchange their parts that happens in prophase 1. And similar chromosomes from mother and father are like a couple. There are 23 chromosomes that came from mother and 23 chromosome that came from Father. In meiosis there is the concept of homologous chromosomes. While chromosome duplication took place prior to meiosis I, no new chromosome replication occurs before meiosis II.Prophase one of the busiest phases of meiosis. In prophase II, the nuclear envelope breaks down and the spindle apparatus forms. Meiosis II begins without any further replication of the chromosomes. This is achieved by a process known as synapsis, where the similar chromosomes pair according to sequence similarity.
What are the differences between prophase of mitosis and prophase 1 of meiosis? The homologous chromosomes pair together in prophase 1 of meiosis, but they do not during prophase 1 of mitosis. Meiosis ends with four haploid cells.Īlso to know is, what is the difference between prophase 1 in meiosis and mitosis? During meiosis 2, the two diploid cells each split into two haploid cells (have half the amount of chromosomes to survive). During meiosis 1, the parent cell with double the normal amount of chromosomes, splits into two diploid cells (have enough chromosomes to survive). Secondly, what is the difference between meiosis 1 and 2? 1 Answer. Prophase I The first is the condensation of chromatin into chromosomes that can be seen through the microscope the second is the synapsis or physical contact between homologous chromosomes and the crossing over of genetic material between these synapsed chromosomes. Then, what happens in prophase 1 and 2 of meiosis? The pairing of homologous chromosomes occurs in Prophase I, whereas such process cannot be seen in Prophase II. There is a long interphase before Prophase I, whereas Prophase II occurs without an interphase. Prophase I is the beginning phase of Meiosis I while Prophase II is the beginning phase of Meiosis II.
0 kommentar(er)
