In the cross between smooth seed coat and wrinkled seed coat, all F1 generation seeds had a smooth coat. Determine the genotypes of the F1 generation and the F2 genotypic ratio.

Question

Asked on April 20, 2026Biology

This biology question covers important biological concepts and processes. The step-by-step explanation below helps you understand the underlying mechanisms and reasoning.

Accepted Answer · 2026-04-20T18:14:43.981Z

Step 1: Determine dominance and assign alleles. In the cross between smooth seed coat and wrinkled seed coat, all F_1 generation seeds had a smooth coat. This indicates that the smooth seed coat trait is dominant over the wrinkled seed coat trait. Let 'S' represent the dominant allele for smooth seed coat. Let 's' represent the recessive allele for wrinkled seed coat. Step 2: Determine the genotypes of the parental (P) generation. Since all F_1 offspring are smooth, the smooth parent must be homozygous dominant (SS) and the wrinkled parent must be homozygous recessive (ss). Parental genotypes: Smooth (SS) × Wrinkled (ss) a) Work out the genotypes of the F_1 generation. To find the F_1 genotypes, we cross the parental genotypes: P: SS × ss Gametes: S from SS, s from ss F_1: Ss All F_1 individuals are heterozygous (Ss) and will express the dominant smooth phenotype. The genotypes of the F_1 generation are: Ss b) From the information above, work out the following for the F_2 generation: The F_1 generation (Ss) was selfed. This means we cross Ss × Ss. Step 1: Perform the F_1 self-cross (Ss × Ss). We can use a Punnett square: | | S | s | |-------|-------|-------| | S | SS | Ss | | s | Ss | ss | b) (i) Genotypic ratio for the F_2 generation. From the Punnett square, the genotypes are SS, Ss, and ss. The ratio of these genotypes is: SS : Ss : ss = 1 : 2 : 1 The genotypic ratio is: 1:2:1 b) (ii) The total number of wrinkled seeds in the F_2 generation. From the Punnett square, the genotype 'ss' corresponds to the wrinkled seed phenotype. The proportion of 'ss' individuals in the F_2 generation is (1)/(4). The total number of F_2 generation individuals is 7324. Number of wrinkled seeds = (Proportion of wrinkled seeds) × (Total F_2 individuals) Number of wrinkled seeds = (1)/(4) × 7324 Number of wrinkled seeds = 1831 The total number of wrinkled seeds is: 1831 b) (iii) Phenotypic ratio for the F_2 generation. From the Punnett square: • SS and Ss genotypes result in the smooth phenotype (dominant). • ss genotype results in the wrinkled phenotype (recessive). So, the phenotypes are Smooth (SS, Ss) and Wrinkled (ss). The ratio of these phenotypes is: Smooth : Wrinkled = (1+2) : 1 = 3 : 1 The phenotypic ratio is: 3:1 Send me the next one 📸

Accepted Answer · 2026-04-20T18:14:43.981Z

Step 1: Determine dominance and assign alleles. In the cross between smooth seed coat and wrinkled seed coat, all F_1 generation seeds had a smooth coat. This indicates that the smooth seed coat trait is dominant over the wrinkled seed coat trait. Let 'S' represent the dominant allele for smooth seed coat. Let 's' represent the recessive allele for wrinkled seed coat. Step 2: Determine the genotypes of the parental (P) generation. Since all F_1 offspring are smooth, the smooth parent must be homozygous dominant (SS) and the wrinkled parent must be homozygous recessive (ss). Parental genotypes: Smooth (SS) × Wrinkled (ss) a) Work out the genotypes of the F_1 generation. To find the F_1 genotypes, we cross the parental genotypes: P: SS × ss Gametes: S from SS, s from ss F_1: Ss All F_1 individuals are heterozygous (Ss) and will express the dominant smooth phenotype. The genotypes of the F_1 generation are: Ss b) From the information above, work out the following for the F_2 generation: The F_1 generation (Ss) was selfed. This means we cross Ss × Ss. Step 1: Perform the F_1 self-cross (Ss × Ss). We can use a Punnett square: | | S | s | |-------|-------|-------| | S | SS | Ss | | s | Ss | ss | b) (i) Genotypic ratio for the F_2 generation. From the Punnett square, the genotypes are SS, Ss, and ss. The ratio of these genotypes is: SS : Ss : ss = 1 : 2 : 1 The genotypic ratio is: 1:2:1 b) (ii) The total number of wrinkled seeds in the F_2 generation. From the Punnett square, the genotype 'ss' corresponds to the wrinkled seed phenotype. The proportion of 'ss' individuals in the F_2 generation is (1)/(4). The total number of F_2 generation individuals is 7324. Number of wrinkled seeds = (Proportion of wrinkled seeds) × (Total F_2 individuals) Number of wrinkled seeds = (1)/(4) × 7324 Number of wrinkled seeds = 1831 The total number of wrinkled seeds is: 1831 b) (iii) Phenotypic ratio for the F_2 generation. From the Punnett square: • SS and Ss genotypes result in the smooth phenotype (dominant). • ss genotype results in the wrinkled phenotype (recessive). So, the phenotypes are Smooth (SS, Ss) and Wrinkled (ss). The ratio of these phenotypes is: Smooth : Wrinkled = (1+2) : 1 = 3 : 1 The phenotypic ratio is: 3:1 Send me the next one 📸

In the cross between smooth seed coat and wrinkled seed coat, all F1 generation seeds had a smooth coat. Determine the genotypes of the F1 generation and the F2 genotypic ratio.

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In the cross between smooth seed coat and wrinkled seed coat, all F1 generation seeds had a smooth coat. Determine the genotypes of the F1 generation and the F2 genotypic ratio.

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