Exploring Mendelian Genetics n Section 11 3 Independent

Exploring Mendelian Genetics n Section 11– 3

Independent Assortment n In a two-factor cross, Mendel followed______ different genes as they passed from one generation to the next. n 2

Independent Assortment n Write the genotypes of the true-breeding plants that Mendel used in his two-factor cross. n Phenotype Genotype a. round yellow peas b. wrinkled green peas __RRYY_ __rryy_

Independent Assortment n Heterozygous dominant with round yellow peas, best describes the F 1 offspring of Mendel’s two-factor cross.

Independent Assortment n Is the following sentence true or false? n The genotypes of the F 1 offspring indicated to Mendel that genes assort independently. n False

Independent Assortment How did Mendel produce the F 2 offspring? n He crossed F 1 plants to each other.

Independent Assortment n Circle the letter of the phenotypes that Mendel would expect to see if genes segregated independently. n a. round and yellow n b. wrinkled and green n c. round and green n d. wrinkled and yellow

Independent Assortment n What did Mendel observe in the F 2 offspring that showed him that the alleles for seed shape segregate independently of those for seed color? n He observed F 2 offspring that had combinations of phenotypes—and therefore combinations of alleles—not found in either parent.

Independent Assortment n What were the phenotypes of the F 2 generation that Mendel observed? n He observed seeds that were round and yellow, wrinkled and green, round and green, and wrinkled and yellow.

Independent Assortment n What was the ratio of Mendel’s F 2 generation for the two-factor cross? n 9 : 3: 3: 1

Introduction to Genetics n Complete the Punnett square below to show the predicted results of Mendel’s two-factor cross.

Introduction to Genetics n State Mendel’s principle of independent assortment. n Genes for different traits can segregate independently during the formation of gametes.

Mendel’s Principles n n n Circle the letter of each sentence that is true about Mendel’s principles. a. The inheritance of biological characteristics is determined by genes that are passed from parents to their offspring. b. Two or more forms of the gene for a single trait can never exist. c. The copies of genes are segregated from each other when gametes are formed. d. The alleles for different genes usually segregate independently of one another.

Intro to Genetics n When two or more forms of the gene for a single trait exist, some forms of the gene ____ may be and others may be _____. n Dominant n Recessive

Genetic Patterns n Is the following sentence true or false? n All genes show simple patterns of dominant and recessive alleles. n false

Patterns of Inheritance n Complete the compare-and-contrast table of the different patterns of inheritance.

n List three criteria Thomas Hunt Morgan was looking for in a model organism for genetic studies. n a. Small in size n b. Easy to keep in the laboratory n c. Able to produce large numbers of offspring in a short time

n Is the following sentence true or false? n Mendel’s principles apply not just to pea plants but to other organisms as well. n True

Genes and Environment n Characteristics are determined by interaction between genes and the ______. n environment