3-1 Mendel’s Work Pages 86 - 91. Early Principles of Inheritance.

3-1 Mendel’s Work

Pages 86 - 91

Early Principles of Inheritance

Tour the basics of genetics

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heredity p 86

•The passing of traits from parents to offspring

heredity

genetics p 86

•The scientific study of heredity

genetics

Gregor Mendel

• Born: July 20, 1822 • Died: January 6, 1884 (aged 61)• Born: Austria-Hungary (now part of Czech

Republic)• Fields: Genetics• Institutions:Abbey of St. Thomas in Brno• Alma mater: University of Vienna• Known for: Discovering genetics• Religious stance: Roman Catholic

Gregor Mendel

• (July 20, 1822 – January 6, 1884) was an Augustinian priest and scientist, and is often called the father of genetics for his study of the inheritance of traits in pea plants.

Gregor MendelMendel showed that the inheritance of traits follows particular laws, which were later named after him. The significance of Mendel's work was not recognized until the turn of the 20th century (1900). Its rediscovery prompted the foundation of the discipline of genetics.

Gregor Mendel

Mendel’s Peas

Mendel’s Peas

Mendel’s Experiments

trait p 86•A characteristic that an organism can pass on to its offspring through its genes

trait

trait

Mendel: some genes are dominant

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The seven traits that Mendel studied in the peas were:

Cross Pollination

purebred p 87

• An organism that always produces offspring with the same form of a trait as the parent

purebred

BB BB BB BB

purebred

B B

B BB BB

B BB BB

Offspring: 100% Black

purebred

BB BB BB BB

Purebred Cross

filial•means “son” in Latin•F1 generation

children

•F2 generation grandchildren

F1 Generation

F1 Generation

F2 Generation

Dominant and Recessive Alleles

gene p 89

•A segment of DNA on a chromosome that codes for a specific trait

gene

allele p 89

•The different forms of a gene

allele

allele

Principle of Dominance

dominant allele p 89

•An allele whose trait always shows up in the organism when the allele is present

dominant allele

Principle of Segregation

recessive allele p 89

•An allele that is masked when a dominant allele is present

recessive allele

recessive allele

Principle of Independent Assortment

hybrid p 90

• An organism that has two different alleles for a trait; an organism that is heterozygous for a particular trait

hybrid

Dd x Dd

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Mendel’s Law of Genetic Inheritance

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