Question 1: Define the term 'chloroplast' and explain its role in plant cells.

Answer: Chloroplasts are organelles in plant cells that contain chlorophyll and are responsible for photosynthesis, converting light energy into chemical energy.

Question 2: Describe the function of the cell wall in plant cells.

Answer: The cell wall provides structural support and protection, maintaining the shape of the plant cell.

Question 1: A plant cell's chloroplast is measured to be 5 micrometres in length under a microscope with a magnification of 1000x. Calculate the actual length of the chloroplast in micrometres.

Answer: 0.005

Question 2: The diameter of a plant cell in an image is 2.5 cm when viewed under a microscope with 400x magnification. What is the real diameter of the cell in micrometres?

Answer: 6.25

Question 1: Describe how you would prepare a slide to observe the nucleus of a plant cell using a microscope. Include safety precautions.

Answer: To prepare a slide, cut a thin section of plant tissue, place it on a clean slide, add a drop of iodine stain to stain the nucleus, cover with a coverslip, and observe under a microscope. Safety precautions include wearing gloves when handling chemicals and ensuring the microscope is used on a stable surface.

Question 1: A student measures the length of a root tip cell to be 0.05 mm under 1000x magnification. If the actual length of the cell is 50 micrometres, what is the magnification used? Show your working.

Answer: 1000

Question 1: Explain how the structure of the xylem vessel relates to its function in transporting water in plants.

Answer: Xylem vessels are long, hollow tubes with thick walls reinforced by lignin, which provides structural support and prevents collapse. Their hollow structure allows efficient transport of water and minerals from the roots to the leaves.

Question 2: A plant cell has a chloroplast volume of 20 cubic micrometres and a total cell volume of 100 cubic micrometres. What percentage of the cell volume is occupied by chloroplasts?

Answer: 20%

Question 1: Discuss how understanding the structure of plant cells can contribute to advances in agricultural biotechnology.

Answer: Understanding plant cell structure helps in developing genetically modified crops with improved traits such as disease resistance, drought tolerance, or higher yield by targeting specific cell components or pathways.