Using a Punnett square, determine the genotype and phenotype ratios of the offspring from a cross between two red-yellow apple trees (Ry x Ry).

Here are the solutions to the questions: 3.3.1 Step 1: Identify the genotypes and phenotypes of the parents. Parents: Red yellow apple × Red yellow apple Genotypes: Ry × Ry Step 2: Determine the gametes produced by each parent (Meiosis). Gametes from first parent (Ry): R, y Gametes from second parent (Ry): R, y Step 3: Perform the genetic cross using a Punnett square (Fertilisation). |c|c|c| Gametes & R & y \\ R & RR & Ry \\ y & Ry & yy \\ Step 4: Determine the genotypes and phenotypes of the offspring. Genotypes: RR, Ry, Ry, yy Phenotypes: • RR: Red apple • Ry: Red yellow apple • yy: Yellow apple 3.3.2 Step 1: Count the number of offspring with genotype Ry. From the Punnett square in 3.3.1, there are 2 offspring with the genotype Ry out of 4 total possible offspring. Step 2: Express this as a proportion. The proportion of offspring with genotype Ry is (2)/(4) = (1)/(2). The proportion of offspring with genotype Ry is (1)/(2). 3.3.3 Step 1: List the phenotypes and their corresponding genotypes from 3.3.1. • Red apple: RR • Red yellow apple: Ry • Yellow apple: yy Step 2: Determine the phenotypic ratio of the offspring. From the Punnett square, the genotypes are 1 RR : 2 Ry : 1 yy. Therefore, the phenotypic ratio is: 1 Red apple : 2 Red yellow apple : 1 Yellow apple The phenotypic ratio of the offspring is 1 Red apple : 2 Red yellow apple : 1 Yellow apple.