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Making a Pedigree Chart. Miguez Biology. Quick Review. Genotype=what genes someone has Genes are usually represented by a letter, a capital letter for the dominant trait, a small case for the recessive. Ex. Tongue Rolling is dominant, so we use R to represent the tongue rolling
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Making a Pedigree Chart Miguez Biology
Quick Review • Genotype=what genes someone has • Genes are usually represented by a letter, a capital letter for the dominant trait, a small case for the recessive. • Ex. Tongue Rolling is dominant, so we use R to represent the tongue rolling • Inablilty to roll your tongue is recessive so we use r to represent the non-rolling gene • For every trait, you get a gene from each parent
Genotypes and Phenotypes • Mom and Dad are Rr-that is their genotype, they can also be described as heterozygous-they have 1 of each gene • What is their PHENOTYPE? • The youngest son has a genotype of rr-he is Homozygous recessive-2 copies of the recessive gene • His phenotype? tongue rollers Rr Rr I can’t Roll my Tongue! Rr rr Rr Rr non-roller
Some common dominant and recessive traits • Widow’s peak is dominant. • You can be homozygous dominant (WW) or heterozygous (Ww) and you will have widow’s peak • What is your genotype and phenotype if you’re homozygous recessive? ww, no widow's peak
Making a Pedigree Chart • Pedigree charts are made to chart family history and see how traits are passed • What generations are these? P1 F1 F2
Symbols Used-write it down! • Shade individuals that have the trait you’re studying • Boys=squares (Lucy always calls Charlie Brown a ‘block head’) • Girls-circles
Married-connected at side • Siblings-connected at TOP not at the side (hopefully not siblings AND married) • Oldest child-to the left • Question-if shaded individuals in this pedigree have blue eyes, what is the GENOTYPE of the parents? both must be Bb