1In a study of phytoplankton productivity, a scientist uses a log10 scale on the y-axis to plot net primary productivity against phosphorus concentration. If the productivity value increases from 1.0 to 3.0 on the log scale, by what factor has the actual productivity increased?
2When investigating the effectiveness of disinfectants using the disc diffusion method, a student notices that the mean diameter of the clear zone for Hypochlorite is 15mm (SD ±3) and for Chlorhexidine is 12mm (SD ±4). Which statement best evaluates these results?
3A potometer is used to estimate the rate of transpiration in a plant shoot. Why does this apparatus usually provide an overestimation of the actual rate of transpiration?
4In an experiment investigating the effect of sodium chloride concentration on potato cylinder mass, a student calculates the percentage change in mass. What is the primary advantage of using percentage change rather than absolute mass change?
5A statistical test on the correlation between caffeine intake and brain cancer risk yields a P value of < 0.01. What is the correct interpretation of this value?
6Scientists studying the growth of pigs used subjects of the same breed and similar genotypes. What is the biological justification for this experimental control?
7Why are small tadpoles affected more rapidly by water-borne pesticides than adult toads of the same species?
8A researcher observes a strong positive correlation between vehicle exhaust concentration and asthma cases over 5 years. Why is it incorrect to conclude that exhausts cause asthma based only on this data?
9In an ecosystem study, scientists measured CO2 release from leaves, stems, and soil organisms. Why might this data fail to represent the total respiration of the ecosystem?
10When using a transect to investigate marram grass distribution across a sand dune, what is the most appropriate method to ensure the data is representative?
