Question 1: Define antibiotics and explain how they target bacterial cells without harming human cells.

Answer: Antibiotics are substances that kill bacteria or inhibit their growth by targeting specific bacterial structures or enzymes, such as the bacterial cell wall or protein synthesis machinery, which are different from those in human cells, thus preventing harm to human cells.

Question 2: Describe the difference between bacterial and viral infections in terms of their structure and the effectiveness of antibiotics.

Answer: Bacterial infections are caused by single-celled organisms with cell walls and metabolic processes, which antibiotics can target. Viral infections are caused by viruses that lack cellular structure and rely on host cells for reproduction; antibiotics are ineffective against viruses.

Question 3: Explain why antibiotics are not effective against viral infections.

Answer: Because viruses do not have the cellular structures or metabolic pathways that antibiotics target, so antibiotics cannot kill or inhibit viruses.

Question 1: A patient is prescribed 500 mg of an antibiotic to be taken four times a day for 7 days. Calculate the total amount of antibiotic the patient will consume in milligrams.

Answer: Total amount = dose per intake × number of intakes = 500 mg × 4 × 7 = 14,000 mg

Question 2: If a bacterial population reduces by 90% after one dose of an antibiotic, what percentage remains after the second dose, assuming the same effectiveness?

Answer: Remaining percentage after second dose = 10% of 10% = 1%

Question 1: Design a simple experiment to test the effectiveness of a new antibiotic against bacterial growth in a laboratory setting. Include variables and safety precautions.

Answer: Students should propose setting up agar plates inoculated with bacteria, applying the antibiotic to some plates while leaving others as controls, measuring zones of inhibition. Variables include antibiotic concentration (independent), bacterial strain (controlled), and temperature (controlled). Safety precautions include sterilising equipment, wearing lab coats and gloves, and proper disposal of bacterial cultures.

Question 2: Explain why overuse of antibiotics can lead to antibiotic resistance and the implications for public health.

Answer: Overuse of antibiotics creates selective pressure that encourages bacteria to develop resistance genes, making infections harder to treat and increasing the risk of antibiotic-resistant strains spreading, which poses a serious threat to public health.

Question 1: A clinical trial tested the effectiveness of two antibiotics, A and B, against bacterial infections. Antibiotic A showed a 95% success rate in clearing infections in 100 patients, while Antibiotic B showed an 80% success rate in 120 patients. What can be concluded about the relative effectiveness of the two antibiotics?

Answer: Antibiotic A appears more effective than Antibiotic B in clearing infections, but further statistical analysis would be needed to determine if the difference is significant.

Question 1: Discuss how the development of new antibiotics can benefit society, considering the threat of antibiotic resistance.

Answer: Developing new antibiotics can provide effective treatments against resistant bacteria, reduce mortality and morbidity from infections, and help manage emerging resistant strains, thus safeguarding public health and maintaining effective disease control.

Question 2: Suggest measures that healthcare professionals and patients can take to prevent the rise of antibiotic resistance.

Answer: Healthcare professionals should prescribe antibiotics only when necessary, ensure complete courses are taken, and promote good hygiene. Patients should follow prescriptions correctly, avoid self-medicating, and not demand antibiotics for viral infections.