Inheritance and Selection Overview

Inheritance and Selection Overview

1. Past Targets

   • Label diagrams in more depth

2. Key Terms

   • Genotype - the genetic constitution of an organism
   • Phenotype - the expression of the genotype and its interaction with the environment
   • Allele - alternative versions of the same gene
     • The alleles at a specific locus may be either homozygous or heterozygous
     • Alleles may be dominant, recessive or codominant
     • There may be multiple alleles of the same gene
   • Locus - where the gene is located on the allele
   • Homozygous - where both alleles are the same
   • Heterozygous - where both alleles are different

3. Genetic Crosses

   • Dominant - Von Willebrands Disease
   • Recessive - Cystic Fibrosis
   • Codominant - Sickle Cell Anaemia

4. Hardy Weinberg

   • Conditions
     • No Mutations
     • No Migration
     • Random Mating
     • Random Fertility
   • Gene Pool - all of the alleles in a population
   • Allele Frequency - the percentage of the allele in a population
   • Equation 1: p^2+2pq+q^2=1
   • Equation 2: p+q=1
   • Provides a mathematical model which predicts that allele frequencies will not change from generation to generation

5. Selection

   • Directional
   • Stabilising

6. Speciation

   • Mist
     • Mutation
     • Isolation
     • Selection
     • Time
   • Geographic Isolation separates gene pools causing changes in them
   • Reproductive Isolation - when the changes lead to the two populations becoming incompatible

Images and files in the map