Ratio of complementary genes is:
Correct answer: D. 9 : 7
- A. 9 : 3 : 4
- B. 12 : 3 : 1
- C. 9 : 3 : 3 : 1
- D. 9 : 7
Explanation
The correct answer is 9 : 7 (Option D). Complementary gene interaction occurs when two different genes work in tandem, with the presence of at least one dominant allele from each gene necessary for the expression of a specific trait. This results in a phenotypic ratio of 9 : 7. Other options such as 9 : 3 : 4, 12 : 3 : 1, and 9 : 3 : 3 : 1 represent different types of genetic interactions or inheritance patterns, like epistasis and Mendelian dihybrid crosses, but do not pertain to complementary gene interactions.
Last updated
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.
Practise Inheritance
1,238 free Inheritance MCQs from Biology, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Exams that ask Biology questions like this
Biology is on 6 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
Related questions
4 Mutations in opsin genes cause_ types of colorblindness.
9 : 3 : 3 : 1 ratio is given by:
A bald man marries to pattern bald woman. The chance of baldness in their daughter is:
A botanist sees that when he breeds a plant with blue flowers and a plant with red flowers, the resulting generation are plants with a 1:1 ratio of blue: red flowers. He knows that the two parents are homozygous for the trait of color. What phenomenon most likely explains the 1:1 ratio in the filial generation?
A carrier female for hemophilia can pass the defective allele to: