Question 1: Define a bacterial cell and describe one key difference between bacterial cells and eukaryotic cells.

Answer: A bacterial cell is a prokaryotic cell lacking a nucleus, characterised by a cell wall, cell membrane, cytoplasm, and genetic material. Unlike eukaryotic cells, bacterial cells do not have membrane-bound organelles.

Question 2: Explain how bacterial cells reproduce and mention the process involved.

Answer: Bacterial cells reproduce primarily by binary fission, where the cell grows, duplicates its genetic material, and divides into two identical daughter cells.

Question 3: Describe the function of the bacterial flagellum.

Answer: The bacterial flagellum is a tail-like structure that enables bacteria to move by rotating, allowing them to navigate their environment.

Question 4: Identify the component of a bacterial cell responsible for protecting the cell and giving it shape.

Answer: The cell wall provides protection and maintains the shape of the bacterial cell.

Question 1: A bacterial cell has a diameter of 2 micrometers. Calculate its surface area in square micrometers, using the formula for the surface area of a sphere (4πr²).

Answer: Surface area = 4 * π * (radius)^2 = 4 * 3.14 * (1)^2 = 12.56 square micrometers.

Question 2: If a bacterial cell divides every 20 minutes, how many bacteria will be present after 2 hours starting from a single cell? (Assume binary fission and no environmental limitations).

Answer: Number of divisions = 2 hours / 20 minutes = 6. Number of bacteria = 2^6 = 64.

Question 1: Describe a safe method to observe bacteria under a microscope, including safety precautions to prevent contamination.

Answer: Use sterile techniques such as sterilising the slide and cover slip, wearing gloves, and working in a clean environment. Dispose of bacterial cultures properly to prevent contamination.

Question 2: Identify two variables that could affect the growth of bacteria in a culture experiment and suggest how to control them.

Answer: Variables include temperature and nutrient availability. Control by maintaining constant temperature and providing a standard nutrient medium.

Question 1: A bacterial culture was sampled every hour for 6 hours. The population count was as follows: 100, 200, 400, 800, 1600, 3200. Explain what this data indicates about bacterial growth and identify the pattern.

Answer: The data shows exponential growth, doubling each hour, indicating rapid reproduction of bacteria under optimal conditions.

Question 1: Which component of a bacterial cell is primarily responsible for genetic information storage?

Answer: Plasmid

Question 2: Bacterial cells lack membrane-bound organelles. True or False?

Answer: True

Question 3: Describe how bacteria can be useful in industry, providing at least one example.

Answer: Bacteria are used in industry for processes like fermentation to produce products such as yoghurt, cheese, and antibiotics. They help in biotechnology applications due to their ability to rapidly reproduce and carry out specific biochemical reactions.

Question 1: Explain how understanding bacterial cell structure can assist in developing antibiotics.

Answer: Understanding bacterial cell structures, such as cell walls and ribosomes, allows scientists to target these components with antibiotics, disrupting bacterial growth and survival without harming human cells.

Question 2: Discuss the importance of bacteria in the nitrogen cycle and its impact on agriculture.

Answer: Bacteria play a vital role in the nitrogen cycle by fixing atmospheric nitrogen into forms usable by plants, such as ammonium. This process enriches soil fertility, reducing the need for chemical fertilisers and promoting sustainable agriculture.