Question 1: Define bacteria and describe their basic structure.

Answer: Bacteria are microscopic single-celled organisms with a cell wall, cell membrane, cytoplasm, and genetic material. They lack a nucleus and often have structures like flagella or pili for movement and attachment.

Question 2: Explain how bacteria reproduce. Include the term for this process.

Answer: Bacteria reproduce mainly through a process called binary fission, where a single bacterial cell divides into two identical daughter cells.

Question 3: Multiple Choice: Which of the following structures help bacteria move?

Answer:

Question 4: Fill in the blank: Bacteria that cause illness are called ________ bacteria.

Answer: pathogenic

Question 5: Describe two ways bacteria can cause disease in humans.

Answer: Bacteria can cause disease by producing toxins that damage tissues, and by invading and multiplying within the body, leading to infections.

Question 6: Calculate the number of bacteria after 3 hours if a single bacterium divides every 20 minutes. Show your working.

Answer: Number of divisions = 3 hours / (20 minutes / 60) = 3 / (1/3) = 9 divisions. Starting with 1 bacterium, total bacteria = 2^9 = 512.

Question 7: Identify two common methods to prevent bacterial infections.

Answer: Using antibiotics to kill bacteria and practicing good hygiene, such as handwashing, to prevent bacterial spread.

Question 8: Discuss the role of antibiotics in treating bacterial infections. Include one limitation of antibiotics.

Answer: Antibiotics are medicines that kill bacteria or inhibit their growth, helping to treat bacterial infections. A limitation is that bacteria can develop resistance to antibiotics, making some infections harder to treat.

Question 9: Explain the importance of personal hygiene and sanitation in controlling bacterial infections.

Answer: Personal hygiene and sanitation help remove bacteria from the skin and environment, reducing the risk of bacteria entering the body and causing infections.

Question 10: Describe an experiment to test the effectiveness of handwashing in removing bacteria. Include variables and safety precautions (theory only).

Answer: To test handwashing effectiveness, students could swab their hands before and after washing with soap and water, then culture the samples on agar plates to observe bacterial growth. Variables include the method of handwashing (independent variable) and bacterial reduction (dependent variable). Safety precautions involve wearing gloves and sterilizing equipment.