Page 1: Introduction to Mendel and Classical Genetics

This page introduces Gregor Mendel's foundational work in classical genetics and his revolutionary approach to studying heredity through pea plants. The content explains how Mendel's systematic experiments led to the discovery of inheritance patterns.

Definition: Classical genetics refers to the study of heredity and trait inheritance patterns established through Mendel's experimental work.

Highlight: Mendel's work contradicted the prevailing "blending inheritance" theory of his time, which incorrectly suggested that parental traits simply mixed in offspring.

Example: Mendel studied 32 different varieties of pea plants, establishing "pure lines" through self-pollination to ensure consistent inherited traits.

Vocabulary:

• Phenotype: Observable characteristics of an organism
• Genotype: Genetic makeup determined by allele pairs
• Dominant traits: Characteristics that mask recessive traits
• Recessive traits: Characteristics that only appear when both alleles are recessive

Page 2: The Punnett Square and Independent Assortment

This page details the practical application of Mendel's laws through the quadrato di punnett (Punnett square) and explains the concept of independent assortment of genes.

Definition: The Punnett square is a diagram used to predict the possible genotypes of offspring based on parental genetics.

Example: A cross between yellow-smooth (GGLL) and green-wrinkled (ggll) pea plants demonstrates the 9:3:3:1 ratio in the F2 generation.

Highlight: The law of independent assortment states that alleles of different genes segregate independently during gamete formation.

Vocabulary:

• Test cross: Experimental breeding between an organism with unknown genotype and one with known recessive traits
• F1 generation: First generation offspring
• F2 generation: Second generation offspring from F1 crosses

The page concludes with practical applications of test crosses and their importance in determining unknown genotypes.