[eSVT] La méiose et la production de gamètes

This video presents the phases of meiosis and the behavior of chromosomes. Meiosis is a double cell division that occurs in the gonads (ovary, testis, etc.) and allows the formation of four gametes, haploid (n) daughter cells, from a diploid (2n) mother cell. The first division is reductional and allows the transition from a 2n=4 cell to an n=2 (haploid) cell through the separation of chromosome pairs in anaphase 1. The second division of meiosis is equational and preserves the chromosomal equation: n=2 is retained. However, during this division, the homologous chromatids of each double chromosome are separated, which allows for an equitable distribution of chromosomal material. Meiosis produces gametes that are all different (genetic diversity), unlike mitosis, which forms identical cells. 00:00 Introduction to Meiosis 00:28 Meiosis: General Information 00:43 Prophase 1 and Diploid Cells 01:25 Metaphase 1 and Chromosome Alignment 02:31 Anaphase 1 and Homologous Chromosome Separation 03:32 Telophase 1 and Cytokinesis 04:28 Summary of the First Meiotic Division: Reductional Division 04:52 Prophase 2 05:16 Metaphase 2 06:13 Anaphase 2 and Homologous Chromatid Separation 07:27 Telophase 2 and Gamete Formation 08:13 Diagram Title 08:32 Credits Recommended Level: Year 11 (Science and Biology) Source: http://m.pourcher.free.fr Note: This video was produced as part of the 1st-year Specialty SVT Success Book (Hatier). Official video: https://www.hatier-clic.fr/22csvt151 Source: https://www.editions-hatier.fr/livre/...