Mendels Experimente und Vererbungsregeln

Mendel's Experiments and Inheritance Rules

• Gregor Mendel (1822-1884) discovered fundamental rules of inheritance through experiments with pea plants.
• His findings form the basis of modern genetics.

Experimental Setup and Methods

• Subjects: Pea plants
• Advantages: Large number of offspring quickly, distinct traits (e.g., flower color).
• Methods: Self-pollination (allowing plants to pollinate themselves); cross-pollination (using a brush to transfer pollen).
• Features: Clear phenotypic variations (e.g., violet vs. white flowers.)

Mendel's Approach

• Studied individual traits in detail (e.g., flower color).
• Bred purebred plants (P generation).
• Analyzed offspring generations (F1 and F2).

Mendel's Laws

1. Law of Uniformity

• When two purebred individuals with differing traits are crossed, all offspring in the F1 generation are identical.
• Example: Crossing purebred violet and purebred white flowers yields only violet flowers in the F1 generation.

2. Law of Segregation

• When F1 generation hybrids are crossed, traits segregate in a predictable manner.
• Example: Crossing F1 generation violet flowers yields a 3:1 ratio of violet to white flowers in the F2 generation. 1/4 homozygous dominant (violet), 1/2 heterozygous (violet), 1/4 homozygous recessive (white).

3. Dominant and Recessive Traits

• Dominant trait: The trait that visibly appears when at least one dominant allele (e.g., violet flower) is present
• Recessive trait: A trait that only manifests if both recessive alleles (e.g., white flower) are present.

Significance of Mendel's Rules

• Foundation of modern genetics.
• Explains inheritance patterns for many traits.
• Applications in breeding, medicine, and evolutionary biology.

Gregor Mendel entdeckte grundlegende Regeln der Vererbung durch Experimente mit Erbsenpflanzen. Seine Ergebnisse bilden die Grundlage der modernen Genetik. Er untersuchte einzelne Merkmale im Detail und analysierte die Nachfolgegenerationen.