HMB265H1 Lecture Notes - Lecture 17: Cleft Lip And Cleft Palate, Chromosome Abnormality, Indel

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

Document Summary

Lecture 17 large-scale chromosomal changes i: changes in chromosome number. Changes in chromosome number: we were discussing consequences of single base-pair mutations, we can have duplications and indel mutations, but sometimes we also have whole chromosomes in excess or depleted. Lecture 17 outline: euploidy, monoploidy, polyploidy, aneuploidy, monosomy, trisomy, genome restructuring and evolution. Two classes of chromosomal changes: euploidy involves a change in the number of sets of chromosomes. If we have one set or multiple sets of chromosomes in diploid organisms: aneuploidy involves complete homologous sets, but missing a single chromosome, genome restructuring is important in speciation and evolution. Changes in chromosome number: need to preserve the genetic material in order for a species to maintain itself, but sometimes there are errors. If we start from a diploid individual, we can end up with monoploidy: embryonic lethal in humans, all cases of polyploidy are embryonic lethal in humans. For autosomes : monosomy is lethal in humans (except chromosome 21)