In a genetic cross having recessive epistasis, F2 phenotypic ratio would be
Correct answer: C. 9 : 3 : 4
- A. 9 : 6 : 1
- B. 15 : 1
- C. 9 : 3 : 4
- D. 12 : 3 : 1
Explanation
In a genetic cross having recessive epistasis, F2 phenotypic ratio would be 9 : 3 : 4. The recessive epistasis is illustrated by coat colour in mouse, the coat colour is determined by A/a pair, recessive allele b is epistatic over A/a. Thus, in the presence of bb, both A and aa give the same phenotype (albino). The F2 ratio is generally 9 : 3 : 4.
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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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