Inheritance

Meiosis and the Production of Genetically Different GametesSign up

know that a locus is the location of a gene on a chromosome; understand the linkage of genes on a chromosome · understand the role of meiosis in producing non-identical gametes via independent assortment in metaphase I and crossing over in prophase I (stage names of prophase not required) · understand how mammalian gametes are specialised for their functions (acrosome in sperm, zona pellucida in the egg)

Monohybrid Genetics: Codominance, Multiple Alleles, Sex Linkage and Test CrossesSign up

understand the terms gene, allele, genotype, phenotype, recessive, dominant, codominance, homozygote, heterozygote · understand patterns of inheritance including monohybrid inheritance and genetic pedigree diagrams · understand sex linkage on the X chromosome (red-green colour blindness) · understand how the cystic fibrosis gene mutation impairs gaseous exchange, digestive and reproductive systems · understand uses of genetic screening (carrier identification, PGD, prenatal testing including amniocentesis and chorionic villus sampling) and the implications of prenatal screening · identify and discuss ethical and social issues relating to genetic screening (religious, moral and social viewpoints)

Dihybrid Crosses, Autosomal Linkage, Epistasis and the Chi-Squared TestSign up

interpret and construct genetic diagrams, including Punnett squares, to predict the results of dihybrid crosses involving dominance, codominance, multiple alleles and sex linkage (16.2.2) · interpret and construct genetic diagrams for dihybrid crosses involving autosomal linkage and epistasis (knowledge of expected epistasis ratios not required) (16.2.3) · interpret and construct genetic diagrams for dihybrid test crosses (16.2.4) · use the chi-squared test to test the significance of differences between observed and expected results, with the formula provided (16.2.5)

Genes, Proteins and Phenotype: Genetic Disorders and GibberellinSign up

explain the relationship between genes, proteins and phenotype with respect to the four required examples: TYR gene / tyrosinase / albinism; HBB gene / haemoglobin / sickle cell anaemia; F8 gene / factor VIII / haemophilia; HTT gene / huntingtin / Huntington's disease (16.2.6). NOTE: seed al-edx-bio-1.2-lesson-6 contributes only a generic 'mutations cause genetic disorders' sentence (already consumed by the primary derivation al-cie-bio-6-lesson-2); all four named examples are authored fresh · explain the role of gibberellin in stem elongation, including the dominant allele Le coding for a functional enzyme in the gibberellin-synthesis pathway and the recessive allele le coding for a non-functional enzyme, and the effect on phenotype/plant height (16.2.7) - entirely absent from the seed

Gene Control: the lac Operon and Eukaryotic/Plant Gene RegulationSign up

describe the differences between structural genes and regulatory genes, and the differences between repressible enzymes and inducible enzymes (16.3.1) · explain genetic control of protein production in a prokaryote using the lac operon (role of cAMP not required) (16.3.2) · state that transcription factors are proteins that bind to DNA and are involved in controlling eukaryotic gene expression by decreasing or increasing the rate of transcription (16.3.3) · explain how gibberellin activates genes by causing the breakdown of DELLA protein repressors, which normally inhibit factors that promote transcription (16.3.4)