Heredity and Evolution Cheat Sheet

Key Definitions

• Heredity: Transmission of traits from parents to offspring.

• Gene: Basic unit of heredity, made of DNA.

• Allele: Variant form of a gene.

• Genotype: Genetic makeup of an organism.

• Phenotype: Observable characteristics of an organism.

Important Concepts

Mendelian Genetics

• Law of Segregation: Alleles segregate during gamete formation.

• Law of Independent Assortment: Genes for different traits are inherited independently.

Evolution

• Natural Selection: Process where organisms better adapted to their environment tend to survive and produce more offspring.

• Mutation: Change in DNA sequence, a source of genetic variation.

• Speciation: Formation of new and distinct species.

Key Formulas

• p: Frequency of dominant allele.

• q: Frequency of recessive allele.

p² + 2pq + q² = 1

• p²: Frequency of homozygous dominant genotype.

• 2pq: Frequency of heterozygous genotype.

• q²: Frequency of homozygous recessive genotype.

Common Mistakes to Avoid

Common Mistake: Confusing genotype with phenotype; remember genotype is genetic makeup, phenotype is the physical expression.

Memory Tricks

Tip: "HAP" — Heredity, Alleles, Phenotype — helps remember key concepts in heredity.

Key Diagrams

Mendel's Pea Plant Experiment
   _________
  |         |
  |   P1   |   (Parental Generation)
  |_________|
        |
        |   F1 (First Filial Generation)
        v
   _________
  |         |
  |   F1   |
  |_________|
        |
        |   F2 (Second Filial Generation)
        v
   _________
  |         |
  |   F2   |
  |_________|