Questions: Comparing the phenotypic and genotypic ratio of a monohybrid cross for a gene that shows an incomplete dominance reveals that in the F2 generation the genotypic ratio is 1:2:1 while phenotypic ratio is 3:1, the genotypic ratio is the same as phenotypic ratio, all of the F2 are of the same genotype and phenotype (all heterozygous), the genotypic ratio is 3: 1 while phenotypic ratio is 1: 2: 1

The answer is the second one: the genotypic ratio is the same as phenotypic ratio.

Explanation for each option:

1. The genotypic ratio is 1:2:1 while phenotypic ratio is 3:1: This is incorrect. In a monohybrid cross with incomplete dominance, the phenotypic ratio is not 3:1. The 3:1 ratio is typical for complete dominance.

2. The genotypic ratio is the same as phenotypic ratio: This is correct. In incomplete dominance, the heterozygous phenotype is distinct from both homozygous phenotypes, resulting in a 1:2:1 phenotypic ratio that matches the genotypic ratio.

3. All of the F2 are of the same genotype and phenotype (all heterozygous): This is incorrect. In the F2 generation of a monohybrid cross with incomplete dominance, there are three different genotypes (homozygous dominant, heterozygous, and homozygous recessive).

4. The genotypic ratio is 3:1 while phenotypic ratio is 1:2:1: This is incorrect. The genotypic ratio in incomplete dominance is 1:2:1, not 3:1.

In summary, for a monohybrid cross with incomplete dominance, the genotypic and phenotypic ratios in the F2 generation are both 1:2:1.