1. A researcher is investigating the effect of pH on the activity of an enzyme. They set up five experiments, each with the same concentration of enzyme and substrate, but at different pH levels: 4.0, 5.0, 6.0, 7.0, and 8.0. They measure the rate of product formation in each experiment. The results show that the enzyme activity is highest at pH 7.0 and decreases as the pH deviates from this value. Which of the following conclusions can be drawn from these results?

2. A researcher is studying the effects of a new drug on the growth of bacteria. They inoculate 15 petri dishes with the same strain of bacteria and expose them to different concentrations of the drug. After 24 hours, they measure the diameter of the bacterial colonies in each dish. The researcher wants to determine if there is a statistically significant difference in the diameter of the bacterial colonies between the different drug concentrations. Which statistical test would be most appropriate for the researcher to use?

3. A researcher is investigating the effect of different concentrations of a drug on the survival of a population of bacteria. They inoculate five petri dishes with the same initial number of bacteria and expose them to different concentrations of the drug. After a fixed time, they count the number of surviving bacteria in each dish. Which of the following is the best way to analyze the data and determine the effect of the drug concentration on bacterial survival?

4. A researcher is studying the effects of a new drug on the growth of bacteria. They inoculate 4 petri dishes with the same strain of bacteria and expose them to different concentrations of the drug. After 24 hours, they measure the diameter of the bacterial colonies in each dish. Which of the following is the best way to analyze the data and determine the effect of the drug concentration on bacterial growth?

5. A researcher is investigating the effect of a new fertilizer on the growth of tomato plants. They set up an experiment with two groups: one group receives the new fertilizer, and the other group (the control) receives no fertilizer. After 4 weeks, they measure the height of each plant. Which statistical test should the researcher use to analyze the data and determine if there is a significant difference in plant growth between the two groups?

6. A researcher is studying the effects of a new drug on the survival of cancer cells in a petri dish. They expose the cancer cells to different concentrations of the drug and measure the percentage of cells that survive after 48 hours. The researcher wants to determine the minimum concentration of the drug that is effective in killing at least 95% of the cancer cells. Which of the following methods would be most appropriate for the researcher to use to determine this?

7. A researcher is investigating the effect of temperature on the solubility of a salt in water. They set up four experiments, each with the same volume of water and the same amount of salt, but at different temperatures: 10°C, 20°C, 30°C, and 40°C. They measure the amount of salt that dissolves in each experiment. Which of the following graphs would best represent the relationship between temperature and the solubility of the salt?

8. A researcher is investigating the effect of light intensity on the rate of photosynthesis in a plant. They set up four experiments, each with the same plant species and growth conditions, but with different light intensities: 100 lux, 500 lux, 1000 lux, and 2000 lux. They measure the rate of oxygen production in each experiment as an indicator of the rate of photosynthesis. The results show that as the light intensity increases, the rate of photosynthesis increases, but only up to a certain point. Beyond this point, the rate of photosynthesis decreases. Which of the following conclusions can be drawn from these results?

9. A researcher is investigating the effect of temperature on the rate of a chemical reaction. They set up four experiments, each with the same starting concentrations of reactants, but at different temperatures: 10°C, 20°C, 30°C, and 40°C. After a fixed time interval, they measure the concentration of the product formed in each experiment. Which of the following graphs would best represent the relationship between temperature and the rate of the chemical reaction?

10. A biologist is studying the effect of light intensity on the growth of a plant species. They set up four growth chambers, each with the same soil, water, and nutrient conditions, but with different light intensities. After a fixed time, they measure the height of the plants in each chamber. Which of the following is the best way to analyze the data and determine the effect of light intensity on plant growth?