Shortcut Methods
Principles of Inheritance and Variation:
1. Mendel’s Experiments:
Gregor Mendel conducted experiments with pea plants, studying traits like flower color, seed shape, and pod color.
2. Mendel’s Laws:
Law of Dominance:
Dominant alleles mask the expression of recessive alleles.
Dominant alleles are represented by uppercase letters (e.g., A), and recessive alleles by lowercase letters (e.g., a).
Law of Segregation:
Alleles segregate during gamete formation.
Gametes carry only one allele for a trait.
Law of Independent Assortment:
Alleles of different genes segregate independently during gamete formation.
Assortment of alleles for one trait doesn’t influence another trait.
3. Genotype and Phenotype:
Genotype: Genetic makeup (e.g., AA, Aa, aa).
Phenotype: Observable trait (e.g., purple flowers, white flowers).
4. Punnett Squares:
Used to predict offspring genotypes and phenotypes in genetic crosses.
5. Monohybrid and Dihybrid Crosses:
Monohybrid: Study of one trait inheritance.
Dihybrid: Study of two different trait inheritances simultaneously.
6. Variations:
Differences in traits among individuals.
Result from different allele combinations inherited from parents.
7. Role in Evolution:
Variations and natural selection drive the evolution of species.
