L'origine du génotype des individus - Term spé SVT - Madame SVT

Did you like this video? Will it help you get a good grade on your next assessment? Give me a like and subscribe so I know! 😊 To support my work, you can leave a tip here ➡️ https://fr.tipeee.com/madame-svt I'M ON INSTAGRAM: @madame.svt -   / madame.svt   - ON FACEBOOK "Madame SVT" -   / madame.svt   - AND ON TIKTOK: https://vm.tiktok.com/ZMd7Ukf1S/ Link to the revision sheet to download ➡️ https://drive.google.com/file/d/1YXqF... The chapter "The Origin of Individual Genotypes" This lesson falls under Theme 1, "Earth, Life, and the Organization of Living Things," of the final year of high school science (SVT) specialization. Knowledge and skills covered in this chapter, according to the official curriculum guidelines: The succession of mitoses produces a clone, that is, a set of cells, all genetically identical except for mutations. These clones are made up of separate cells or cells that are stably associated. In the absence of genetic exchange with the outside world, the genetic diversity within a clone results from the accumulation of successive mutations in the different cells. Any irreversible genetic mutation becomes permanent for the entire lineage (subclone) that derives from the mutant. Fertilization between haploid gametes brings together, in a single diploid cell, two genomes of independent origin, each contributing a set of alleles. Each resulting pair of alleles consists of two identical alleles (homozygosity) or two different alleles (heterozygosity). At the end of meiosis, each cell produced receives only one of the two alleles from each pair with equal probability. For two pairs of alleles, four allele combinations are possible, with equal probability or not in the case of linked genes. The number of possible genetic combinations in gametes is higher when the number of genes in the heterozygous state is greater in the parents. Genetic analysis can be based on the study of the hereditary transmission of observable traits (phenotype) in crosses most often derived from pure (homozygous) lines and differing only by a limited number of traits. In the case of the human species, the identification of the alleles carried by an individual relies first on a study within the family, applying the principles of hereditary transmission of traits. The development of DNA sequencing techniques and advances in bioinformatics provide direct access to the genotype of each individual, as well as those of their ancestors and descendants. The use of computerized databases makes it possible to identify associations between certain mutated genes and certain phenotypes. Abnormalities can occur during meiosis… These accidents, often lethal, sometimes lead to significant diversification of genomes and play a crucial role in biological evolution. Happy studying! 😉 Theme music: "Atlantis" by Scandinavianz (   • Atlantis – Scandinavianz (No Copyright Music)  ) 0:00 Introduction 0:34 I. GENOME CONSERVATION: GENETIC STABILITY AND CLONAL EVOLUTION 3:46 II. The Shuffling of Genomes in Each Generation: Sexual Reproduction in Eukaryotes 9:58 III. Understanding the Results of Sexual Reproduction: Basic Principles of Genetics 15:06 IV. Genetic Errors in Meiosis