Non mendelian genetics(roel)

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Non mendelian genetics(roel)

  1. 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. 2. Answer this!? <ul><li>A homozygous round seed crosses with a homozygous wrinkled seed. Give the genotype and the phenotype of the offspring. </li></ul>
  3. 3. <ul><li>What if you marry an American man o woman? What do you think would be your children look like? </li></ul><ul><li>Think! Think! Think! </li></ul>
  4. 4. Non-Mendenlian Inheritance <ul><li>is a general term that refers to any pattern of inheritance in which traits do not segregate in accordance with Mendel’s laws. </li></ul>
  5. 5. Incomplete Dominance <ul><li>is a form of intermediate inheritance in which one allele for a specific trait is not dominant over the other allele. </li></ul>
  6. 6. Example
  7. 7. Remember! <ul><li>“ 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.” </li></ul>
  8. 8. Codominance <ul><li>the &quot;recessive&quot; & &quot;dominant&quot; traits appear together in the phenotype of hybrid organisms. </li></ul><ul><li>Both alleles contribute to the phenotype of the organism by showing up simultaneously (at the same time) in heterozygous individuals. </li></ul>
  9. 9. Example R = allele for red flowers W = allele for white flowers red x white ---> pink RR x WW ---> 100% RW
  10. 10. Remember! <ul><li>“ 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 . ” </li></ul>
  11. 11. Sex Chromosomes <ul><li>MALES: </li></ul><ul><li>- have non-identical sex chromosomes (XY). </li></ul><ul><li>FEMALES: </li></ul><ul><li>- have identical sex chromosomes (XX). </li></ul>
  12. 12. Sex Determination
  13. 13. Sex-linked traits <ul><li>This is also referred to as “x-linked traits”. </li></ul><ul><li>These are determined by genes that are carried on the X chromosomes. </li></ul><ul><li>This is determined also in the sex chromosomes of an individual. </li></ul>
  14. 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. 15. Sex-linked trait
  16. 16. Sex-influenced traits <ul><li>The traits produced here is not sex-linked, but is carried by the body chromosomes or AUTOSOMES. </li></ul><ul><ul><li>Example of this is Baldness. </li></ul></ul>
  17. 17. Assignment # 1 <ul><li>Directions: Answer the following questions. Write your answers on a short bond paper. COPY and ANSWER. </li></ul><ul><li>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. </li></ul><ul><li>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. </li></ul>

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