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Non mendelian genetics(roel)

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  • 1. Non-Mendelian Genetics (Non-Mendelian Patterns of Inheritance) -Incomplete dominance -Codominance -Sex determination -Sex-linked traits Roel R. Maraya BEEdBSEd 4-1 (Natural Sciences) January 19, 2010
  • 2. Answer this!?
    • A homozygous round seed crosses with a homozygous wrinkled seed. Give the genotype and the phenotype of the offspring.
  • 3.
    • What if you marry an American man o woman? What do you think would be your children look like?
    • Think! Think! Think!
  • 4. Non-Mendenlian Inheritance
    • is a general term that refers to any pattern of inheritance in which traits do not segregate in accordance with Mendels laws.
  • 5. Incomplete Dominance
    • is a form of intermediate inheritance in which one allele for a specific trait is not dominant over the other allele.
  • 6. Example
  • 7. Remember!
    • With incomplete dominance , a cross between organisms with two different phenotypes produces offspring with a third phenotype that is a blending of the parental traits.
  • 8. Codominance
    • the "recessive" & "dominant" traits appear together in the phenotype of hybrid organisms.
    • Both alleles contribute to the phenotype of the organism by showing up simultaneously (at the same time) in heterozygous individuals.
  • 9. Example R = allele for red flowers W = allele for white flowers red x white ---> pink RR x WW ---> 100% RW
  • 10. Remember!
    • With codominance , a cross between organisms with two different phenotypes produces offspring with a third phenotype in which both of the parental traits appear together .
  • 11. Sex Chromosomes
    • MALES:
    • - have non-identical sex chromosomes (XY).
    • FEMALES:
    • - have identical sex chromosomes (XX).
  • 12. Sex Determination
  • 13. Sex-linked traits
    • This is also referred to as x-linked traits.
    • These are determined by genes that are carried on the X chromosomes.
    • This is determined also in the sex chromosomes of an individual.
  • 14. Genotypes and Phenotypes of Color Blindness in Humans Color-blind male 5. X c Y Normal male 4. XY Color-blind female 3. X c X c Normal female,carrier of the gene 2. XX c Normal female 1. XX Phenotypes Genotypes
  • 15. Sex-linked trait
  • 16. Sex-influenced traits
    • The traits produced here is not sex-linked, but is carried by the body chromosomes or AUTOSOMES.
      • Example of this is Baldness.
  • 17. Assignment # 1
    • Directions: Answer the following questions. Write your answers on a short bond paper. COPY and ANSWER.
    • 1. Suppose a heterozygous woman (genotype X c X) marries a color blind man (genotype X c Y), determine the phenotypes of their children using a Punnett square.
    • 2. Suppose a color-blind woman (X c X c ) th a normal marries a man with a normal vision (XY), determine the phenotypes of their children using a Punnett square.
  • 18.