<p>Dragon Genetics , An overview (summary of PowerPoint in MS Word I’m all Keyed Up • Upper case letter - dominant allele, Lower case letter - recessive allele • An allele is one of two or more alternate forms of the same gene or segment of DNA on a chromosome. • Each allele carries the genetic information that codes for specific traits - eg. Neck length • Alleles pair up to create complete code for genetic trait Alleles Dominant when it completely masks the presence of allele it is paired with • Masked trait is recessive • Long necks dominant to short necks, N - long necks, n - short necks • NN, Nn, nn are possible genotypes Would Someone Please Take Charge • Single trait inheritance: one allele from mom, one allele from dad • Combination of alleles – genotype, Physical expression - phenotype • NN - genotype, long neck - phenotype Do Your Ears Hang Low? • If your phenotype indicates the expression of the dominant trait, you probably don’t know the genotype. Why? • If your phenotype indicates the expression of the recessive trait, you will know your genotype. Why? Do your tongues roll? • RR – homozygous Rr - heterozygous rr homozygous • Zygoun = to join, homo = same, hetero = different • RR and Rr = tongue rollers, rr= non tongue-rollers Enter the Dragon • Thomas Morgan and other performed experiments with Drosophila, the fruit fly, and provided proof that genes are arranged linearly on chromosomes. • Mendel postulated: each trait is determined by two factors (genes), one from the mother and one from the father AND genes exhibit dominance and recessiveness Gene vs Allele • A gene is a segment of DNA located at a particular place along a chromosome • Each gene or DNA segment codes for a specific trait, Alleles are the various versions of each gene • Example: gene- blood type, various version of gene (alleles) code for different blood types. One allele codes for A, a second codes for B and a third codes for O type blood. Dragon Combinations • 13 dragon traits with two possibilities each • That’s 213 possible combinations or 8 192 possible dragons. • Sixteen possible dragons can be formed during activity 5. • There are four chromosomes in each set. • Haploid # = 4, Diploid # = 8 • Blue paper = father dragons ( sperm) • Pink paper = mother dragons (eggs) Sex Determination • The mother always donates an X chromosome to her offspring, while the father may donate either an X chromosome or a Y chromosome. XX = female, XY = male • This not only codes for gender, but secondary sex characteristics such as ear frills • XX dragon = female, but she will never have ear frills • XY dragon = male, with ear frills</p>