Presentation on theme: "Warm-up Complete these crosses. Give the possible genotypic results and phenotypic results. Free ear lobes are dominant to attached ear lobes in humans."— Presentation transcript:
1 Warm-upComplete these crosses. Give the possible genotypic results and phenotypic results.Free ear lobes are dominant to attached ear lobes in humans. If a recessive male marries a homozygous dominant female, what will be the phenotypic and genotypic ratios of their offspring?Give the phenotypic and genotypic ratios of the possible offspring produced, when a heterozygous brown-eyed man marries a heterozygous brown-eyed woman. Brown eyes are dominant over blue eyes which are recessive.
2 Agenda Warm-up Notes Practice Worksheets Whiteboards Clean-Up Cool-down
8 Mendel’s Principles of Inheritance Inherited traits are transmitted by genes which occur in alternate forms called allelesPrinciple of Dominance - when 2 forms of the same gene are present the dominant allele is expressedPrinciple of Segregation - in meiosis two alleles separate so that each gamete receives only one form of the genePrinciple of Independent Assortment - each trait is inherited independent of other traits (chance)
9 If we saw an organism that had round seeds (round is dominant), how could we figure out what its genotype is?
18 Polygenic TraitPolygenic traits are traits that are influenced by several genes. Examples include human height and skin color, which are both influenced by dozens of genes.As a result of polygenic traits, a lot of intermediate conditions exist.Genes with 3 or more alleles have multiple alleles. An example of multiple alleles is blood (IA, IB, IO)
19 Blood TypeThe four Blood types are: A, B, AB, and O that come from the three alleles IA, IB, IOA and B are codominant, and they are also dominant to O.Type A = IAIA or IAIO, Type B = IBIB or IBIO, Type AB = IA IB, and Type O = IOIO
20 Codominance-neither allele is dominant, but both are expressed at the same time
21 IT’S A MUSTWhen a combination of the dominant and recessive allele make a new intermediate trait...
32 Draw the cross and give the genotypic and phenotypic ratios of the cross of a red flower and a pink flower.Red- hom. domPink- het.White- hom. rec.
33 You found a tall pea plant You found a tall pea plant. Explain how you would determine the genotype of this plant.*Hint in pea plants, short height is recessive.What are the possible genotypes of the plant?b. Draw Punnett squares for your possible crosses.c. You have 24 offspring, 24 tall and 0 short plants. What was the genotype of the plant?
34 THANK YOU!! Clean up this room!! That means… No paper or trash on the floorChairs tucked under the desksDesks straightTHANK YOU!!
35 Cool-Down1- Give an example of a phenotype and a genotype. 2- What is the difference between homozygous and heterozygous? 3- Perform a cross with RR x rr? What % of offspring would express the dominant trait?