SCSA Biology Science Inquiry Skills
5 sample questions with marking guides and sample answers · Avg. score: 68%
The purpose of a 'control' in an experiment is to
determine the reliability of the experiment.
provide a comparison for the experimental treatment.
reduce the sample sizes needed for the experiment to be valid.
minimise the number of variables to be tested.
A bacterial pathogen causes eye disease in finches. Biologists wanted to know whether the finches could evolve resistance to this pathogen. Finches from a population that had prior exposure to the pathogen, and from a population that had no prior exposure, were infected with the pathogen deliberately. After two weeks, the biologists determined the pathogen load in the two groups of finches. The independent variable in this experiment is the
deliberate infection of finches with the pathogen.
prior exposure of a population to the pathogen.
two-week duration of the experiment.
pathogen load in the two groups of finches.
The table shows data from a transect study along a sand dune.
| Zone | ||||
|---|---|---|---|---|
| A | B | C | D | |
| Distance from sea (m) | 0–100 | >100–150 | >150–250 | >250–300 |
| Age of dune (years) | 0–50 | >50–100 | >100–125 | >125–150 |
| pH of soil | 8.4 | 7.4 | 6.9 | 6.0 |
| Organic matter in soil (%) | 1 | 2.5 | 5 | 30 |
| Number of grass species | 2 | 4 | 6 | 2 |
| Number of tree species | 0 | 1 | 3 | 8 |
Contrast species richness in zones A and D. Refer to data in your response.
Infer how organic matter affects the pH of soil. Justify your response.
Predict which zone would have the highest proportion of K-selected species. Explain your reasoning.
A student designed and conducted a practical investigation to test for the presence of microbes in water and food samples.
Justify a safety precaution required to prevent infection when conducting the investigation.
Explain how the student could ensure the reliability of the investigation.
Describe a feature that distinguishes a viral from a bacterial pathogen.
A waterborne disease outbreak occurred after a flood.
Outline an experimental procedure that could be used to determine if the pathogen is viral or bacterial.