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What is the phenotypic ratio for a cross between a plant with blue flowers (BB) and a plant with white flowers (bb)?

Correct answer: D. All blue

  • A. 25% blue, 75% white
  • B. 75% blue, 25% white
  • C. All white
  • D. All blue

Explanation

The phenotypic ratio for a cross between a plant with blue flowers (BB) and a plant with white flowers (bb) would be 100% blue. In this case, the parent plants are homozygous for their respective flower colors, meaning they have two identical alleles for flower color (BB and bb). When they are crossed, all of their offspring will inherit one allele from each parent, resulting in all the offspring having the genotype Bb. This genotype represents the heterozygous condition for flower color, which expresses the dominant blue flower color phenotype.

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About Inheritance

Mendel's laws explain segregation, independent assortment and the prediction of genetic ratios using alleles, genotypes and phenotypes. The chapter also covers linked genes, recombination and crossing over during meiosis, then applies pedigree reasoning to X-linked recessive traits, which show different inheritance patterns in males and females.

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