Chapter 16 Syllabus

16.1 Mendelian Genetics
- Definition of the terms gamete, gene, allele, dominant and recessive alleles, homozygote, heterozygote, phenotype, genotype, filial generation (P1, P2, F1, F2), type of crosses (test cross, back cross, reciprocal cross, selfing) and pure cross
- Mendel's experiment on monohybrid and dihybrid crosses/inheritance
- Characteristics of pea plants used by Mendel

16.1.1 Monohybrid
- Monohybrid cross and its results
- Mendel's first law (Law of Seggregation) and its relation to meiosis
- Calculations of genotypic and phenotypic ratios (Punnett square and branch/fork method)

16.1.2 Dihybrid
- Dihybrid cross and its results
- Mendel's second law (law of Independant assortment) and its' relation to meiosis
- Calculations of genotypic and phenotypic ratios until F2 generation (Punnett square and branch/fork methods)

16.2 Modification of Mendelian Genetics
- Crosses that result in ratios differing from the classic Mendelian 3:1 and 9:3:3:1 ratios

16.2.1 Codominance
- Definition
- Examplke of inheritance: MN blood group in humans
- Calculations of genotypic and phenotypic ratios

16.2.2 Incomplete Doiminance
- Definition
- Example of inheritance : Antirrhinum (snapdragon) flower colour
- Calculations of genotypic and phenotypic ratios

16.2.3 Multiple Alleles
- Definition
- Example of inheritance: human ABO blood group
- Calcuylations of genotypic and phenotypic ratios

16.2.4 Lethal Genes
- Definition
- Example of inheritance: coat colour in mice
- Calculations of genotypic and phenotypic ratios

16.2.5 Polygenes
- Definition
- Example of inheritance: height in humans

16.2.6 Linked Genes
- Definition of linked genes and sex-linked genes
- Effect of crossing over on ratio of dihybrid crosses
- Parental and recombinant phenotypes
- Examples: Drosophila eye colour and haemophilia in humans
- Calculations of genotypic and phenotypic ratios
- Pedigree analysis
- Sex determination in humans

16.2.7 Epistasis
- Definition and examples only

16.3 Genetic Mapping
- Calculayions of distance between two loci based on percentage of cross-over
- Examples of calculations for Drosophila
-Determining the relative position of a gene on a chromosome based on percentage of cross-over