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Alleles. Two alleles for each gene Half from your mom and half from your dad A capital letter for dominant allele and a lower-case letter for the recessive allele Dominant allele takes over a recessive allele Recessive produces only when its paired allele is identical
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Alleles • Two alleles for each gene • Half from your mom and half from your dad • A capital letter for dominant allele and a lower-case letter for the recessive allele • Dominant allele takes over a recessive allele • Recessive produces only when its paired allele is identical • The dominant chromosome is represented as XH • The recessive chromosome is represented as Xh
HemophiliaPunnett Squares XH Y • Punnett squares are used to show the probability of receiving a genetic disorder from a parent. XH XHXH XHY XHXh XhY Xh Xh Y Xh Y XH XHXh XHY XH XHXh XHY XH XHXh XHY XhXh Xh XhY
Punnett Square Probability Ratios: 2: 2: 2 XHXh2 XHY Percentages: 50%: 50%: 50% XHXh 50% XHY Xh Y XH XHXh XHY XH XHXh XHY
Punnett Squares Genotypes and Phenotypes • What do the letters mean ? • Uppercase letters represent dominant genes • Lowercase letters represent recessive genes • H is the dominant allele ,which is red • h is are the recessive allele , which is black Xh Y Phenotype/What We See H = Red Hh = Red (Black Gene Carrier) XH XHXh XHY XH XHXh XHY Genotype/What Is In Our Genes His the Homozygous dominant (Red) Hh is the heterozygous dominant (Red w/ Black)