Question 1: Define surface area to volume ratio and explain its importance in biological systems.

Answer: Surface area to volume ratio is the ratio of an organism's or cell's surface area to its volume. It is important because it affects the efficiency of nutrient uptake and waste removal; smaller objects have higher ratios, facilitating faster exchange.

Question 2: Explain why smaller cells generally have a higher surface area to volume ratio compared to larger cells.

Answer: Smaller cells have a higher surface area relative to their volume because as size increases, volume increases faster than surface area, reducing the ratio and affecting exchange efficiency.

Question 1: Calculate the surface area and volume of a cube with an edge length of 2 cm. Then, determine its surface area to volume ratio.

Answer: Surface Area = 24 cm²; Volume = 8 cm³; Ratio = 3 cm⁻¹

Question 2: A spherical cell has a diameter of 10 μm. Calculate its surface area, volume, and the surface area to volume ratio. Use π ≈ 3.14.

Answer: Surface Area ≈ 314 μm²; Volume ≈ 523.6 μm³; Ratio ≈ 0.6 μm⁻¹

Question 1: Describe a simple experimental setup to compare the surface area to volume ratios of different shaped objects, including variables to control and safety precautions.

Answer: Students can use objects like cubes, spheres, and cylinders made from similar materials. Variables to control include material type, size, and environmental conditions. Safety precautions involve handling sharp tools carefully and wearing protective equipment when cutting or shaping objects.

Question 1: A large cell has a surface area of 1500 μm² and a volume of 3000 μm³. A smaller cell has a surface area of 600 μm² and a volume of 800 μm³. Which cell has a higher surface area to volume ratio, and what does this imply about their efficiency in nutrient exchange?

Answer: The smaller cell has a higher surface area to volume ratio (0.75 μm⁻¹ vs. 0.5 μm⁻¹), implying it is more efficient in nutrient exchange relative to its size.

Question 1: Explain how the surface area to volume ratio affects the design of small robots or nanotechnology devices intended for biological applications.

Answer: Devices designed for biological applications need high surface area to volume ratios to facilitate efficient exchange of substances, mimicking cellular behaviour for better integration and functionality.

Question 1: Describe how surface area to volume ratio influences the size and shape of cells within multicellular organisms. Include examples to support your answer. (6 marks)

Answer: Cells need to maintain a high surface area to volume ratio to efficiently exchange nutrients and wastes. Smaller or elongated shapes increase this ratio, aiding in faster exchange. For example, the elongated shape of nerve cells increases surface area for signal transmission, while red blood cells have a biconcave shape to optimise gas exchange.