The Work of Gregor Mendel - Every living thing has a set of characteristics inherited from its parent or parents. - Heredity makes each species unique. -Genetics is the scientific study of heredity.
Gregor Mendel’s Peas
- Austrian monk. - His work with pea plants set the framework for our understanding of inheritance, how genes are passed on to offspring. - Pea plants are normally self-pollinating - seeds (offspring) produced inherit all of the characteristics from the single plant that bore them. - Mendel’s peas were true-breeding - if allowed to self-pollinate, offspring are identical to parent plant. - Mendel wanted to cross two different plants, so he prevented self-pollination by removing the male parts of the plant. Then he dusted pollen from another plant on the flower without the male parts. This process is called cross-pollination. The offspring had two different plants as parents. - A trait is a specific characteristic (seed colour or plant height) that varies from one individual to another. - The 7 traits that Mendel studied had two contrasting characters (tall, short; yellow, green). - The different forms of a gene are called alleles. - Example = the gene for plant height produces tall plants or short plants. Tall and short are the alleles. - Each original pair of plants is called the P generation. P = parental. - Offspring are called the F1 generation. F1 = first filial. Filius or filia are the Latin words for “son” and “daughter”. - Hybrids are offspring of crosses between parents with different traits. - Mendel drew 2 conclusions from his first set of crosses: 1) Biological inheritance is determined by factors that are passed from one generation to the next. 2) Principle of dominance - some alleles are dominant and others are recessive.
- An organism with a dominant allele for a particular form of a trait will always exhibit that form of the trait.
- An organism with a recessive allele for a particular form of a trait will...