Neco 2021 Biology Question 3

A group of students were asked to determine the starch content of three food samples (Sample A – boiled potato, Sample B – white rice, Sample C – banana) using the iodine test. The procedure was as follows: 1. Prepare a 1% iodine solution. 2. Weigh 2.0 g of each food sample, grind to a fine paste and add 20 mL of distilled water. 3. Add 2 drops of iodine solution to each test tube and observe the colour change. 4. To quantify the starch, a spectrophotometer was used at 620 nm. A standard curve was prepared using starch solutions of known concentration as shown below. Standard Curve Data (Absorbance at 620 nm): Concentration (mg mL⁻¹) : 0  2  4  6 Absorbance : 0.00 0.15 0.30 0.45 Absorbance readings for the unknown samples were recorded as follows: Sample A : 0.38 Sample B : 0.10 Sample C : 0.28 Using the information above, answer the following questions: