BIOL 1010 Lecture Notes - Lecture 3: Consanguinity, Glaukos, Lethal Allele
20 Aug 2018
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Document Summary
22 pairs of homologous chromosomes - same for male and female karyotype. Last pair 23rd - of the human karyotype. Diseases that have a genetic component plus a significant environmental influence. The genetic component is also polygenetic (many genes, not just one that cause it) No matter the genotype, lifestyle has an effect. Forms have multiple causes: genetic predisposition and environmental (depends = multifactorial) Incidence: variable, 1/15 in western population tend to have this disorder. Person carries an extra y chromosome on sex chromosomes (only males) 3 types: nondisjunction of autosomal chromosomes during meiosis i (left part of the sketch) Error in separating the homologue chromosomes during meiosis i. Result in one side containing more chromosomes than the other side before meiosis ii. They will properly separate into sister chromatids at meiosis ii. One half of the gametes will have one more chromosomes. The other half of the other gametes will have one less chromosomes.
