Which of the following phenotypic results are expected from a dihybrid cross?
Correct answer: B. 9:3:3:1 ratio
- A. 1:1:1:1 ratio
- B. 9:3:3:1 ratio
- C. All dominant for both traits
- D. All recessive for both traits
Explanation
Both the product rule and the Punnett Square approaches showed that a 9:3:3:1 phenotypic ratio is expected among the progeny of a dihybrid cross such as Mendel's RrYy × RrYy. In making these calculations, we assumed that: both loci assort independently; one allele at each locus is completely dominant; and.
Report an error
The more specific you are, the faster it gets fixed. A source beats an opinion.
Prefer email? [email protected]
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.
Discussion
Stuck on an option, or know a faster way to get there? Ask or explain it here.
No comments yet. Be the first to explain this one.
Exams that ask Biology questions like this
Biology is on 8 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
More Inheritance questions
The occurrence of affected individuals in every generation in a family suggests which of these traits?
Kathy's brother has cystic fibrosis. Her husband has no family history of CF. What is the chance that Kathy's child has inherited cystic fibrosis?
Two carriers of albinism have four children. One of their children is albino and the remaining three are normally pigmented. What is the probability that their next child will be albino?
Mendel's law states that a random assortment of maternally and paternally derived chromosomes in meiosis results in gametes that have different combinations of these genes.
Which of the following incorrectly identifies the mode of inheritance for the given genetic disease?
Approximately how many human single-gene traits and illnesses are currently known from medical reports?