9.10 HOW DO MEIOSIS AND SEXUAL REPRODUCTION PRODUCE GENETIC VARIABILITY?

Description

Mind Map on 9.10 HOW DO MEIOSIS AND SEXUAL REPRODUCTION PRODUCE GENETIC VARIABILITY?, created by Natalia Lehnhoff Faillace on 13/06/2021.
Natalia Lehnhoff Faillace
Mind Map by Natalia Lehnhoff Faillace, updated more than 1 year ago
Natalia Lehnhoff Faillace
Created by Natalia Lehnhoff Faillace over 3 years ago
68
0

Resource summary

9.10 HOW DO MEIOSIS AND SEXUAL REPRODUCTION PRODUCE GENETIC VARIABILITY?
  1. The individual members of most species are genetically different from one another. The offspring of a single pair of parents are usually genetically different from one another and parents.
    1. Mutations occur randomly.
    2. Shuffling of homologues creates novel combinations of chromosomes
      1. One mechanism is the random distribution of maternal and paternal homologues to the daughter nuclei during meiosis I
        1. During metaphase I the paired of homologues line up at the center of the cell. But which homologs face which pole is random.
        2. In people, meiosis randomly shuffles 23 pairs of homologues chromosome, and theoretically produce more than 8 million (2^23) different combinations of maternal and paternal chromosomes in gametes.
          1. At metaphase I, the chromosomes can align in four possible configurations.
            1. Anaphase I can produce eight possible sets of chromosomes. (2^3 = 8).
          2. Crossing over creates chromosomes with a novel combination of genes
            1. Crossing over produces chromosomes with combinations of alleles that differ from those of either parent.
              1. Some of these new combinations may have never existed before because homologues chromosomes cross over in new and different places at each meiotic division.
              2. 1 in 8 million gametes could have the same combination of maternal and paternal chromosomes.
                1. Crossing over ensures that none of those chromosomes will be purely maternal or purely paternal.
                  1. Every sperm and every egg is genetically unique.
              3. The fusion of gametes adds furthers genetic variability to the offspring
                1. At fertilization, two gametes, each containing a unique combination of alleles, fuse to form a diploid offspring.
                  1. Theoretically, every human can produce about 8 million different gametes based on the random separation of homologues.
                    1. Fusion of just two people could produce 8 million x 8 million, or 64 trillion, genetically different children.
                    2. The chances that your parents could produce another child who is genetically identical the same as you are about 1/8,000,000 x 1/8,000,000 or 1 in 64 trillion.
                    Show full summary Hide full summary

                    Similar

                    GCSE PE - 5
                    lydia_ward
                    A-level Sociology Quiz
                    Chuck Amobi
                    Hitler and the Nazi Party (1919-23)
                    Adam Collinge
                    Chemistry 3 Extracting Metals Core GCSE
                    Chloe Roberts
                    To Kill A Mockingbird GCSE English
                    naomisargent
                    The Crucible Acts 1 and 2 Key Themes and Quotes
                    Matthew T
                    The English Language Techniques
                    craycrayley
                    Maths: Formulas for Areas & Perimeters of Shapes
                    Annan S
                    SalesForce ADM 201 Study Quiz
                    Brianne Wright
                    Repaso Revalida PR 2016
                    Leticia Ortiz del Moral
                    Účto Fífa 5/6
                    Bára Drahošová