Transcript H H
FRIDAY, Nov. 4th You are homozygous dominant for a hairy chest and your sweetie’s heterozygous. Hairy (H) is dominant to not hairy (h). • Draw a punnett square to determine the amount of chest hair your offspring may have! • Tell the possible genotypes and phenotypes of your babies!!! You are homozygous dominant for a hairy chest and your sweetie’s heterozygous. Hairy (H) is dominant to not hairy (h). H H H HH HH h Hh Hh • HH x Hh • • punnet square Tell the possible genotypes and phenotypes of your babies!!! • Genotypes: 50% HH; 50% Hh (1:1) • Phenotypes: 100% hairy-chested, 0% not hairy Longer 2nd toe is dominant over 2nd toe shorter than big toe. Tongue-Rolling: Rolling up edges (dominant trait) vs not rolling (recessive Pinky: Straight pinky (recessive trait) vs. Bent pinky (dominant trait) Mid-digit hair: Mid-digit hair (dominant trait) vs. No mid-digit hair (recessive trait) Dimples: Dimples (dominant trait) vs. No dimples (recessive trait) Thumbs: Straight thumb (dominant trait) vs. Curved thumb (recessive trait) Earlobes: Free ear lobes (dominant trait) vs. Attached ear lobes (recessive trait) Forelock: White forelock (dominant trait) vs. No white forelock (recessive trait) A white forelock is a patch of white hair, usually located at the hairline. Widow's Peak (left) is dominant over no widow's peak hairline. 6.6 KEY CONCEPT Independent assortment and crossing over during meiosis result in genetic diversity!! Genetic diversity!! How the heck does it happen? Random, increases unique combos of genes! 64 trillion combos in humans!!! Indep. asstmt. of chromos increases unique gene combos…8 million diff. combos of chromos in gametes!!! Exchange of chromo segments between hom. chromos during prophase I, new combos of genes, from mom and dad! So, what’s this crossing over thing? • exchange of chromo. segments between homologous chromos! • during prophase I (meiosis I) • results in new combinations of genes Pair up!!! Segments cross!! Remember, chromosomes contain MANY genes!! – Genes located near each other on same chromo usually inherited together!!! – farther apart usually separated by crossing over – Researchers use this to calculate distances on chromosomes…(but you don’t need to know how!) PHUN Punnett Practice Let’s check your answers… Then the Quiz!!