The Work of Gregor Mendel and Applying Mendel's Principles PDF

THE WORK OF GREGOR MENDEL AND APPLYING MENDEL’S PRINCIPLES Chapter 12 Section 1 & 2 Pallavi Rallapalli Mendel’s Experiments Studied how traits are passed from one generation to the next Genetics- the scientific study of biological inheritance Model Organisms- garden peas...

THE WORK OF GREGOR MENDEL AND APPLYING MENDEL’S PRINCIPLES Chapter 12 Section 1 & 2 Pallavi Rallapalli Mendel’s Experiments Studied how traits are passed from one generation to the next Genetics- the scientific study of biological inheritance Model Organisms- garden peas – Small – Easy to grow – Can produce hundreds of offspring Role of Fertilization Trait- a specific characteristic like seed color or plant height Fertilization- when sperm and egg join to make a zygote True Breeding- organisms that produce the same trait over and over Genes and Alleles Genes- DNA that expresses a trait When doing crosses, the initial generation is the P (parental) F1 is the offspring of the P generation and F2 is the offspring of the F1 generation – P  F1  F2 Genes and Alleles Allele- a single form of a gene- represented by a letter – Flower color – Plant height – Pod shape – Pod color – Seed Shape – Seed Color – Flower Position Dominant and Recessive Alleles Dominant Alleles= capital letter Recessive Alleles= Lowercase letter Law of Dominance- states that some alleles are dominant while others are recessive (one will mask the other) – Purple flowers are dominant to white Segregation Law of Segregation- Alleles segregate during meiosis, so each parent only passes on one allele to the offspring Homozygous vs. Heterozygous Homozygous- two alleles that are the same Heterozygous- two alleles that are different Genotype and Phenotype Phenotype- what you physically see (purple flowers) Genotype- the genetic makeup (homozygous or heterozygous) Using a Punnett Square and Independent Crosses Punnett squares are a way of predicting possible genotypes of a cross Mendel’s Overall Conclusions Law of Dominance- One allele is dominant over another Law of Segregation- Parents only pass 1 allele to their offspring Law of Independent Assortment- the alleles of different traits independently assort (do not depend on each other) during the formation of gametes. Mendel Gregor Mendel was the first to correctly predict the process of meiosis and – Law of Segregation- genes separate from each other during gametic cell production Meiosis (meiosis) – Law of Independent Assortment- chromosomes align randomly during meiosis I – Predicting offspring ratios- Mendel could accurately predict the phenotypic ratios of offspring