Incomplete dominance

1. INCOMPLETE DOMINANCE Presented To: Sir Khalid Hussain Presented by :09040606-031

2. Mendel’s Principles Inheritance of biological characteristics is determined by individual units known as genes . During sexual reproduction, genes are passed from parents to offspring. Two or more forms of the gene for a single trait exist, some forms of the gene may be dominant and others may be recessive.

3. What is Incomplete Dominance? Incomplete dominance is a type of inheritance in which one  allele  for a specific trait is not completely dominant over the other allele. This results in a combined  phenotype   (expressed physical trait). 

4. Example……………….. In Four O’ Clocks, if you cross a red RR (which is always pure) with a white WW (that is also always pure) , you get a pink RW (which is always hybrid /heterozygous)

5. Incomplete Dominance

6. Red P ink white

7. Incomplete Dominance In incomplete dominance, neither allele is dominant so there is a blending of traits when two different alleles for the same trait occur together. Colors blend together heterozygous individuals = 3 rd phenotype

8. Incomplete Dominance In another flower, if red RR and blue BB flowers are crossed, they produce a 3 rd purple RB flower What would be the genotype ratio and phenotype ratio if you crossed two purple flowers?

9. Incomplete Dominance Cross of two purple flowers RB X RB genotype ratio 1RR : 2RB : 1BB phenotype ratio 1red : 2 purple : 1 blue B R R B BB RB RR RB red purple purple blue