Mendel’s Work

Key Terms Traits = Physical Characteristics Heredity = Passing of traits from parents to offspring. Genetics = Scientific study of heredity.

Mendel’s Peas

Mendel’s Experiments

Other Traits

Dominant and Recessive Alleles Factors that control traits= Genes Different forms of a gene= Alleles An allele whose trait always shows up in the organism when the allele is present= Dominant allele An allele that is masked whenever the dominant allele is present= Recessive allele

Understanding Mendel’s Crosses P Generation All plants were purebred F1 Generation All plants were Tall All plants were hybrids-They had two different alleles for the trait. F2 Generation ¾ were Tall ¼ were short The short plants must have had two recessive alleles for the trait.

Using Symbols Traits are represented by a capital letter of the Dominant form of the Trait. For Example Tall Pea Plants have at least one dominant allele represented T. Short Pea plants don’t have a dominant allele. If they had a dominant allele they wouldn’t be short. So they have two recessive alleles. tt

Mendel’s Contributions 1866 Mendel presented his findings. Scientists did not understand importance. Scientists thought he oversimplified work. Mendel was discounted because he didn’t work at a university. Mendel could not communicate work because no telephones or computers. Mendel’s work was rediscovered 1900. Many of his theories still stand today.

Mendel is Now Known as the Father of Genetics.