1 / 12

Test Cross- Unknown Genotype

Test Cross- Unknown Genotype. Is the purple plant homozygous or heterozygous ? Perform a test cross! Always! C ross the unknown with a homozygous recessive . Test Cross. Practice! . ? x gg. P. Key: G=green g= yellow. g. G. g. G. g. F 1. Phenotype: 100% green Genotype:

lyre
Download Presentation

Test Cross- Unknown Genotype

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Test Cross- Unknown Genotype • Is the purple plant homozygous or heterozygous ? • Perform a test cross! • Always! Cross the unknown with a homozygous recessive Test Cross

  2. Practice! ? x gg P Key: G=green g= yellow g G g G g F1 Phenotype: 100% green Genotype: 100% heterozygous g G g G g

  3. Practice! ? P ? x gg Key: G=green g= yellow F1 Phenotype: 50% green 50% yellow Genotype:

  4. Incomplete Dominance and Co-Dominance

  5. Incomplete Dominance • Neither allele is dominant • In some cases, an intermediate phenotype is shown

  6. Snapdragons • In snapdragons, flower color can be red, pink, or white. The heterozygous condition results in pink flowers rr Rr RR

  7. Incomplete Dominance Cross Key: R= Red r= White F1 Phenotype: 100% pink F1 Genotype: 100% heterozygous Rr

  8. F1 Cross Key: R= Red r= White Phenotype: 1:2:1 25% Red 25% White 50% Pink Genotype: 1:2:1 25% homozygous RR 25% homozygous rr 50% heterozygous Rr

  9. Other ways to represent incomplete dominance

  10. Co-dominance • Both alleles are expressed equally • Neither allele is more dominant than the other Erminette chickens Roan Cows

  11. Key: B =Black B1= White Co-Dominance Erminette Chicken B B • P generation • Black chicken X White chicken • F1 generation = erminette (checkered patterned) B1 B B1 B B1 B1 B B1 B B1 Phenotype: 4:0 or 1:0 100% erminette Genotype: 4:0 or 1:0 100% heterozygous

  12. Erminette chicken Key: BB =Black BW = White Key: B= Black W= White BB BW BB BB BB BB BW BW BB BW BW BW B1 B2 B1 B1 B1 B1 B2 Key: B1 =Black B2 = White B2 B1 B2 B2 B2

More Related