tailieunhanh - Lecture Biology (6e): Chapter 14 - Campbell, Reece

Chapter 14 - Mendel and the gene idea. This chapter presents the following content: Mendel brought an experimental and quantitative approach to genetics; by the law of segregation, the two alleles for a character are packaged into separate gametes; by the law of independent assortment, each pair of alleles segregates into gametes independently; mendelian inheritance reflects rules of probability; Mendel discovered the particulate behavior of genes. | CHAPTER 14 MENDEL AND THE GENE IDEA Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings Section A: Gregor Mendel’s Discoveries 1. Mendel brought an experimental and quantitative approach to genetics 2. By the law of segregation, the two alleles for a character are packaged into separate gametes 3. By the law of independent assortment, each pair of alleles segregates into gametes independently 4. Mendelian inheritance reflects rules of probability 5. Mendel discovered the particulate behavior of genes: a review Every day we observe heritable variations (eyes of brown, green, blue, or gray) among individuals in a population. These traits are transmitted from parents to offspring. One mechanism for this transmission is the “blending” hypothesis. This hypothesis proposes that the genetic material contributed by each parent mixes in a manner analogous to the way blue and yellow paints blend to make green. Over many generations, a freely mating population should give rise to a uniform population of individuals. Introduction Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings However, the “blending” hypothesis appears incorrect as everyday observations and the results of breeding experiments contradict its predictions. An alternative model, “particulate” inheritance, proposes that parents pass on discrete heritable units - genes - that retain their separate identities in offspring. Genes can be sorted and passed on, generation after generation, in undiluted form. Modern genetics began in an abbey garden, where a monk names Gregor Mendel documented the particulate mechanism of inheritance. Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings Mendel grew up on a small farm in what is today the Czech Republic. In 1843, Mendel entered an Augustinian monastery. He studied at the University of Vienna from 1851 to 1853 where he was influenced by a physicist who encouraged experimentation and the application of . | CHAPTER 14 MENDEL AND THE GENE IDEA Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings Section A: Gregor Mendel’s Discoveries 1. Mendel brought an experimental and quantitative approach to genetics 2. By the law of segregation, the two alleles for a character are packaged into separate gametes 3. By the law of independent assortment, each pair of alleles segregates into gametes independently 4. Mendelian inheritance reflects rules of probability 5. Mendel discovered the particulate behavior of genes: a review Every day we observe heritable variations (eyes of brown, green, blue, or gray) among individuals in a population. These traits are transmitted from parents to offspring. One mechanism for this transmission is the “blending” hypothesis. This hypothesis proposes that the genetic material contributed by each parent mixes in a manner analogous to the way blue and yellow paints blend to make green. Over many generations, a freely mating population should give