In a 3:1 F1 ratio, what is true about the original crossed organisms?

In a 3:1 F1 ratio, this typically indicates a phenotypic ratio resulting from a monohybrid cross where one trait is dominant over another. In this case, the original crossed organisms must include one homozygous dominant and one homozygous recessive individual. When these two parents are crossed, all of the offspring in the F1 generation would be heterozygous, exhibiting the dominant phenotype.

In a subsequent cross of the F1 generation (the heterozygotes), you would then see the 3:1 ratio in the phenotypes of the F2 generation: approximately three offspring displaying the dominant trait for every one displaying the recessive trait.

Therefore, the assertion about the organisms being both heterozygotes does not accurately apply to the initial parental generation; instead, the parents are distinct in that they represent different homozygous genotypes leading to the heterozygous F1 offspring. In summary, while the correct answer does mention heterozygotes, it does not accurately represent the conditions of the original organisms involved in the cross, as they must be homozygous dominant and homozygous recessive, respectively.