Dragon Genetics , An overview (summary of PowerPoint in MS Word by pptfiles

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									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

								
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