Dashboard/Learning Hub/Biology HL/Chapter 4

Biology HL

SLHL

Chapter 4: Genetics

Connect chromosome organization to inheritance, predict simple and complex crosses, infer family genotypes, and test linkage models with recombination and chi-squared evidence.

Estimated chapter time: 509 minutes

IB syllabus: D1.3 · D3.2 · D3.3 · SL and HL

Chapter Topics

Jump directly to any section or subsection.

  1. 1How to Read This Genetics Chapter
    1. 1.1Inheritance Connects Several Scales
    2. 1.2Keep Three Questions Separate
    3. 1.3Evidence Selects Between Models
  2. 2Genomes, Chromosomes and Homologues
    1. 2.1The Genome and Comparative Genomics
    2. 2.2Prokaryotic and Eukaryotic Organization
    3. 2.3Ploidy Counts Homologous Sets
  3. 3Genes, Karyotypes and Sex Chromosomes
    1. 3.1Genes, Loci, Alleles and Phenotype
    2. 3.2Karyograms Display a Karyotype
    3. 3.3Sex Chromosomes and X Inactivation
  4. 4Mendel, Segregation and Punnett Grids
    1. 4.1Mendel Found Particulate Inheritance
    2. 4.2Punnett Grids Enumerate Fertilizations
    3. 4.3Probability and Sample Size
  5. 5Codominance, Multiple Alleles and Incomplete Dominance
    1. 5.1Dominance Is an Allele Relationship
    2. 5.2Multiple Alleles Belong to a Gene Pool
    3. 5.3Context Still Matters
  6. 6Sex Linkage, Pedigrees and Genetic Conditions
    1. 6.1X-linked Alleles Produce Sex-specific Patterns
    2. 6.2Pedigrees Constrain Hidden Genotypes
    3. 6.3Inherited Conditions Link Molecule and Environment
  7. 7Polygenic Inheritance and Phenotypic Plasticity
    1. 7.1Many Loci Create Many Phenotype Classes
    2. 7.2Environment Broadens Genetic Distributions
    3. 7.3Environment Can Determine Sex
  8. 8Dihybrid Crosses, Linkage and Recombination
    1. 8.1Independent Assortment Has Conditions
    2. 8.2Phase Records Which Alleles Share a Homologue
    3. 8.3Recombination Frequency Estimates Distance
  9. 9Chi-squared Testing of Genetic Ratios
    1. 9.1The Null Hypothesis Defines an Expectation
    2. 9.2Calculate a Weighted Deviation
    3. 9.3Interpret Evidence, Not Truth
  10. 10Chapter Synthesis: From Chromosome to Conclusion
    1. 10.1Start with Physical Organization
    2. 10.2Separate Prediction from Observation
    3. 10.3Genotype Is Not Destiny

Previous

3.11 From DNA Sequence to Regulated Phenotype

Next

How to Read This Genetics Chapter