HMB265H1 Lecture Notes - Lecture 8: Prophase, Endosperm, Cytopathology

• School: UTSG
• Department: Human Biology
• Course: HMB265H1
• Professor: Maria Papaconstantinou

Document Summary

Hmb265: lecture 8 - linkage & recombination (oct. 3) Cross 2 pure-breeding parents to get dihybrid individual. In f2 generation, expected 9331 ratios according to mendel"s law of apparent assortment. But didn"t get this (observed very different from expected) Some allelic combinations showed up more frequently than expected in f2. As if alleles physically linked together progeny. Thomas hunt morgan (sex-linkage, conducted certain experiments to support chromosomal theory of inheritance) Studied inheritance of 2 autosomal genes (eye colour + wing shape) Noted departure from mendel"s laws like bateson and punnett. Male = tester parent only carries recessive alleles for 2 genes. Phenotype of f2 progeny = direct reflection of alleles in gametes of f1 dihybrid parent. = can focus on meiosis in dihybrid parent and ignore meiosis in tester parent b/c only contribute recessive alleles. If just do normal testcross (2 dihybrids have to focus on 2 meiotic events) With this just focus on 1 meiotic event.