Question 1: Define an animal cell and explain its role in the body.

Answer: An animal cell is the basic structural and functional unit of animals, responsible for carrying out vital processes such as metabolism, growth, and reproduction.

Question 2: List three key components found in all animal cells and briefly state their functions.

Answer: Nucleus (controls cell activities), Cytoplasm (site of chemical reactions), Cell membrane (regulates what enters and exits).

Question 1: Calculate the surface area to volume ratio of a spherical animal cell with a diameter of 20 micrometres. Use the formulas: Surface Area = 4πr², Volume = (4/3)πr³. Provide your answer in μm²/μm³.

Answer: Surface area = 1256.64 μm²; Volume = 4188.79 μm³; Ratio = 0.30 μm²/μm³

Question 1: Describe a simple experiment to observe animal cells using a microscope. Include the steps, variables to be controlled, and safety precautions.

Answer: Prepare a sample of cheek cells by gently scraping the inside of the cheek with a clean cotton swab, then place it on a microscope slide with a drop of iodine stain. Cover with a cover slip and observe under a microscope at 400x magnification. Control variables include the amount of stain and the focus. Safety precautions involve wearing gloves, handling the microscope carefully, and disposing of biological material properly.

Question 1: A sample of animal tissue shows that the cells have an average diameter of 15 μm. The nucleus occupies approximately 20% of the cell's volume. Discuss what this might indicate about the activity level of these cells.

Answer: The relatively small nucleus occupying 20% of the cell volume suggests moderate activity, as highly active cells often have larger nuclei to support increased gene expression and protein synthesis.

Question 1: Explain the importance of the cell membrane in animal cells and describe how its structure relates to its function. (6 marks)

Answer: The cell membrane is vital for controlling what enters and exits the cell, maintaining homeostasis. Its structure, composed of a phospholipid bilayer with embedded proteins, provides fluidity and selective permeability, allowing the cell to respond to environmental changes while protecting internal components.

Question 1: Discuss how understanding animal cell structure can contribute to advancements in medical treatments, such as targeted drug delivery.

Answer: Knowledge of animal cell structure helps in designing drugs that can target specific cell components, such as receptors on the cell membrane, leading to more effective and less harmful treatments for diseases.