Which of the following is the condition in which many genes affect the same trait? * polygenic inheritance multiple alleles codominance incomplete dominance Which of the following is the condition...

Which of the following is the condition in which many genes affect the same trait? *

  • polygenic inheritance
  • multiple alleles
  • codominance
  • incomplete dominance

Which of the following is the condition in which two different alleles result in a blending of the phenotype? *

  • multiple alleles
  • incomplete dominance
  • polygenic inheritance
  • codominance

If you cross a heterozygous tall plant with a short plant, what are the possible genotypes in the F1? *

  • Tt, tt
  • Tt
  • TT, Tt, tt
  • TT, tt

Which of the following is the condition in which two different alleles are both expressed, but there is not a blending of the phenotype? *

  • polygenic inheritance
  • incomplete dominance
  • multiple alleles
  • codominance

Asked on by cadijoanna

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trophyhunter1 | College Teacher | (Level 1) Educator Emeritus

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In the first question, polygenic inheritance is when two or more genes controls a trait. For example, skin color, height, eye color, to give a few examples, are polygenic. For the second question, incomplete dominance or blending inheritance is when both alleles are present and their effects blend in the phenotype. An example is the Japanese four o clock flower--neither the red nor the white is recessive to the other gene and when a red and a white allele are present in a heterozygote, the flower will be pink--a blending between the two colors. In the third question, regarding height, tall is dominant to short in pea plants. If we represent the heterozygous tall plant as Tt(containing one tall and one short gene) and the short plant as tt(the short plant must be homozygous for the trait to be observed) then the offspring resulting from a cross will be as follows--50% heterozygous tall and 50% short which is the first choice. The final question describes codominance. That is because each gene is expressed at the same time. An example of this would be a person who has sickle cell trait with one normal gene (N) and one sickle cell gene (S) for the production of red blood cells. They would be heterozygous (NS) but, since neither gene is recessive to the other, the person will make normal hemoglobin inside of round red blood cells and abnormal hemoglobin with sickle shaped blood cells.

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