Question 1: Microscopy is the technique used to view objects that are too small to be seen with the naked eye. It involves using devices called microscopes to magnify objects and observe their structure in detail. Different types of microscopes, such as light microscopes and electron microscopes, offer varying levels of magnification and resolution.

Answer: Microscopy is the technique used to view tiny objects by magnifying them with microscopes. Light microscopes use visible light and lenses, while electron microscopes use electron beams for greater magnification and resolution.

Question 1: Define the term 'magnification' in the context of microscopes.

Answer: Magnification is the process of enlarging the appearance of an object through a microscope, making it appear larger than its actual size.

Question 2: Explain the difference between a light microscope and an electron microscope.

Answer: A light microscope uses visible light and glass lenses to magnify specimens, suitable for living samples but with lower resolution. An electron microscope uses electron beams and electromagnetic lenses to achieve much higher magnification and resolution, but it requires dead samples and complex preparation.

Question 1: A specimen appears to be magnified 1000 times under a light microscope. If the actual size of the object is 0.5 mm, what is its apparent size when viewed under the microscope? Show your calculation.

Answer: Apparent size = Actual size × Magnification = 0.5 mm × 1000 = 500 mm

Question 2: A microscope has an eyepiece magnification of 10× and an objective lens magnification of 40×. What is the total magnification?

Answer: Total magnification = Eyepiece magnification × Objective lens magnification = 10 × 40 = 400×

Question 1: Describe a basic procedure for preparing a slide to observe onion cells under a light microscope.

Answer: First, peel a thin layer of onion epidermis and place it on a clean slide. Add a drop of iodine solution to stain the cells. Cover with a coverslip, avoiding air bubbles. Place the slide on the microscope stage and focus using the lowest power objective lens.

Question 2: Identify two variables that must be controlled during microscopy experiments and explain why.

Answer: Magnification and lighting intensity must be controlled to ensure consistent and clear images, preventing distortions or inadequate illumination.

Question 1: A student observes that a cell appears 150 micrometres in size under a microscope with a total magnification of 400×. Calculate the actual size of the cell in micrometres.

Answer: Actual size = Apparent size ÷ Magnification = 150 μm ÷ 400 = 0.375 μm

Question 2: Explain what factors could affect the accuracy of measurements taken using a microscope.

Answer: Factors include the calibration of the microscope, user error in focusing or measuring, the quality and cleanliness of lenses, and the precision of the measuring tools or scales used.

Question 1: Describe how electron microscopy has advanced our understanding of cell structures in biomedical research.

Answer: Electron microscopy has provided extremely detailed images of cell organelles and structures at the molecular level, improving knowledge of cell function, disease mechanisms, and enabling the development of targeted treatments.

Question 2: Identify a technological or medical industry that benefits from microscopy and explain how.

Answer: The pharmaceutical industry benefits from microscopy by analysing cell cultures, drug interactions, and the structure of pharmaceuticals at a microscopic level to ensure quality and efficacy.