Question 1: Define the function of the chloroplast in plant cells.

Answer: Chloroplasts carry out photosynthesis by converting light energy into chemical energy stored as glucose.

Question 2: Explain why plant cells have a cell wall and how it differs from the cell membrane.

Answer: The cell wall provides structural support and protection; it is made of cellulose, whereas the cell membrane controls what enters and exits the cell.

Question 3: Identify two differences between plant and animal cells.

Answer: Plant cells have cell walls and chloroplasts; animal cells do not.

Question 1: Calculate the surface area to volume ratio (SA:V) of the cell in μm⁻¹. Round your answer to two decimal places.

Answer: 0.38

Question 1: Describe the variables you would control and manipulate in this experiment.

Answer: Control variables include light exposure, temperature, and water availability; the independent variable is the type of leaf; the dependent variable is the number of chloroplasts per cell.

Question 2: List two safety precautions to consider when preparing plant samples for microscopy.

Answer: Use gloves to handle chemicals and ensure the microscope is on a stable surface.

Question 1: A study reports that leaf cells from plants grown in high light conditions have an average of 150 chloroplasts per cell, while those grown in low light have 80 chloroplasts per cell. Explain what this suggests about the relationship between light and chloroplast development.

Answer: The data suggests that increased light exposure stimulates the development or proliferation of chloroplasts in plant cells, enhancing the plant's capacity for photosynthesis.

Question 2: A researcher measures the size of a set of plant cells and finds the average diameter to be 25 μm with a standard deviation of 2 μm. What can be inferred about the size variability of these cells?

Answer: Most cells have diameters between approximately 23 μm and 27 μm, indicating relatively low size variability around the mean.

Question 1: Explain how the presence of chloroplasts benefits photosynthetic plant cells in their environment. (6 marks)

Answer: Chloroplasts enable plant cells to carry out photosynthesis, converting light energy into chemical energy stored as glucose. This process provides the plant with energy and organic compounds necessary for growth and development. Chloroplasts also contain chlorophyll, which captures light energy efficiently. Their presence allows plants to produce their own food, supporting survival in various environments.

Question 2: In the context of biotechnology, how might understanding plant cell structures assist in developing genetically modified crops?

Answer: Knowledge of plant cell structures, such as chloroplasts and cell walls, can help scientists engineer crops with improved photosynthesis efficiency, pest resistance, or drought tolerance by targeting specific genes related to these structures.