Lab Report
Lauren Sullivan
Plants Imperfections
Abstract
The purpose of this experiment was to plant different crosses and observe the different phenotypic ratios the plants present. The procedure of this experiment was plant six different crosses and water them correctly so that we could observe the different phenotypes and compare them to Mendel’s proposed ratios. Mendel, who had studied peas, did a similar experiment and came up with specific ratios that a monohybrid and dihybrid cross should show. His findings were that for a monohybrid cross, such as my crosses three and six, the phenotypes would have a ratio of 3:1 (Russell 2003). My results show that cross six fails to reject Mendel’s hypothesis with a ratio of 3 purple to 1 non-purple plant observed. However, cross three did reject Mendel’s hypothesis because epistasis was involved (Strickberger 1985). The results of my last monohybrid cross, cross three, showed a phenotypic ratio of 9 with a yellow tip to 7 all green plants. The dihybrid cross that my group generated showed a 9:3:3:1 ratio of phenotypes, which is the ratio Mendel proposed for such a cross. The phenotypes visible for the dihybrid cross were red stem green leaf, red stem white leaf, no red stem green leaf, and no red stem white leaf.
Introduction
Genetics, which is the science of heredity, has four major areas. One of these areas is called transmission or Mendelian genetics, which deals with the transmission of genes from generation to generation (Russell 2003). Within this area, there are hereditary traits, which are controlled by genes. As studied by Mendel, genotype and phenotype are both characteristics of an organism. Genotype is the genetic make-up of an organism while phenotype is the observable characteristics of an organism. The expression of a trait, phenotype, can be affected by the
Sullivan 2 genetic constitution, genotype, and other genes and environmental factors. Mendel found this out after doing an experiment with peas. He
Plants Imperfections
Abstract
The purpose of this experiment was to plant different crosses and observe the different phenotypic ratios the plants present. The procedure of this experiment was plant six different crosses and water them correctly so that we could observe the different phenotypes and compare them to Mendel’s proposed ratios. Mendel, who had studied peas, did a similar experiment and came up with specific ratios that a monohybrid and dihybrid cross should show. His findings were that for a monohybrid cross, such as my crosses three and six, the phenotypes would have a ratio of 3:1 (Russell 2003). My results show that cross six fails to reject Mendel’s hypothesis with a ratio of 3 purple to 1 non-purple plant observed. However, cross three did reject Mendel’s hypothesis because epistasis was involved (Strickberger 1985). The results of my last monohybrid cross, cross three, showed a phenotypic ratio of 9 with a yellow tip to 7 all green plants. The dihybrid cross that my group generated showed a 9:3:3:1 ratio of phenotypes, which is the ratio Mendel proposed for such a cross. The phenotypes visible for the dihybrid cross were red stem green leaf, red stem white leaf, no red stem green leaf, and no red stem white leaf.
Introduction
Genetics, which is the science of heredity, has four major areas. One of these areas is called transmission or Mendelian genetics, which deals with the transmission of genes from generation to generation (Russell 2003). Within this area, there are hereditary traits, which are controlled by genes. As studied by Mendel, genotype and phenotype are both characteristics of an organism. Genotype is the genetic make-up of an organism while phenotype is the observable characteristics of an organism. The expression of a trait, phenotype, can be affected by the
Sullivan 2 genetic constitution, genotype, and other genes and environmental factors. Mendel found this out after doing an experiment with peas. He
Cited: Sullivan 8 Franks, RL. “Growing Genetic Corn.” Volume 43. Biological Supply Company (1980): 180-181. Heim, Werner G. “What is a Recessive Allele?.” Volume 53. The American Biology Teacher (1991): 35-36. Raven, Peter R., and George B. Johnson. 1996. Biology (4th Ed.). LWMC Brown, Dubuque IA. Russell, Peter J. 2003. Essential Genetics. Benjamin Cummings, New York. 1-10. Strickberger, MW. “Gene Interaction and Lethality.” (1985): 182.