Assuming complete dominance, a phenotypic ratio of ________ is expected from a monohybrid sib or self-cross. A) 1:1 B) 2:1 C) 3:
1 D) 5:2 E) 3:2
1 answer:
Answer:
C (3:1)
Explanation:
Gregor Mendel was able to portray complete dominance of an allele over another when he crossed two purebreeding plants; one homozygous for red flowers and the other for white flowers. He discovered that all the F1 offsprings were red-flowered. Hence, he came up with his law of dominance.
He self-crossed the F1 offsprings which were all hybrids or heterozygous i.e. contained a combined allele in their genotype. He discovered that the offsprings produced a phenotypic ratio of 3:1 i.e 3 red-flowered plants to 1 white-flowered plant
The red-flowered plants have genotypes RR, Rr and Rr respectively while the white-flowered plant have a rr genotype.
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