BICD 100 - Week 3 + overheads

BICD 100 Week 3 - BICD 100 Week 3 Handout Pedigrees Unfortunately(or fortunately genetic experiments cannot be applied to humans Therefore an

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BICD 100 Week 3 Handout: Pedigrees Unfortunately (or fortunately?), genetic experiments cannot be applied to humans! Therefore, an extensive examination of family historical records is often required to elucidate the genetic basis of a particular human condition. - A pedigree is used to accurately depict genetic information in a shorthand form. On a pedigree, is male and is female. Darkened individuals ( ) are affected by the trait (diseased) while blank individuals ( ) are free of the trait (unaffected). Horizontal lines show crosses/sex/mating, and vertical lines show parental/offspring relationship. The top row depicts generation I, followed by subsequent generations in each lower row (II, III, IV and so on). Advice : - Pedigrees are generally straightforward problems that contain a very logical solution. However, it is easy to make careless mistakes , so analyze the problem carefully! assumptions often have to be made about the alleles of unaffected individuals, based on other information in the pedigree be careful not to assume too much or too little. when a problem asks to “identify the genotype of all known individuals”, make sure to look at each individual on the pedigree carefully. think about what is known about that individual, and whether you have enough evidence to unambiguously conclude which alleles they carry. since humans have low numbers of progeny , the inheritance of affected alleles will often not follow precise Mendelian ratios. more deviation is expected when looking at 5 human progeny, compared to looking at 1000 plant progeny. look for
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This note was uploaded on 03/09/2009 for the course BICD bicd 100 taught by Professor Soowal during the Spring '08 term at UCSD.

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BICD 100 Week 3 - BICD 100 Week 3 Handout Pedigrees Unfortunately(or fortunately genetic experiments cannot be applied to humans Therefore an

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