SACE Stage 2 Biology: mixed exam-style practice quiz

The volume of carbon dioxide produced in 20 minutes

The temperature of the flasks, which is kept at 30 °C

The concentration of the glucose solution

The mass of yeast added to each flask of solution

The pH of the glucose solutions

The colour of the flasks used in the experiment

The time of day at which each flask is set up

The name of the yeast supplier printed on the packet

To increase the reliability of the results by adding a sixth repeat of the experiment

To act as a controlled variable that stays constant in every flask in the experiment

To show the maximum rate of respiration that yeast can reach under these conditions

To act as a control, showing how much carbon dioxide is produced without added glucose

A bar graph, because each concentration is a separate category

A line graph, because both variables are continuous

A pie chart, because the volumes add up to a total amount

A histogram, because the data show a frequency distribution

Volume rose steeply from 1 mL to 15 mL up to 4 percent, then levelled off near 20 mL

Volume rose steadily and in direct proportion across every glucose concentration

Volume increased as glucose increased, showing that glucose causes respiration

Volume was highest at 8 percent, so 8 percent is the optimum glucose concentration

A random error, which reduces the precision of the results

A systematic error, which is removed by repeating trials

A random error, which is removed by calculating a mean

A systematic error, which reduces the accuracy of the results

To remove any systematic error caused by poorly calibrated measuring equipment

To make sure that the results will support the hypothesis being tested

To reduce the effect of random errors and allow the reliability of results to be judged

To increase the number of independent variables that can be tested at once

Light intensity will have some kind of effect on pondweed in the experiment

As light intensity increases, the number of oxygen bubbles produced per minute will increase

Pondweed needs light to survive, so it will die in the dark in the end

The rate of photosynthesis will be measured using light at different intensities

Suspect B's profile matches the crime-scene sample at all three regions

Suspect A's profile matches, because two of its fragments are the same

All three suspects match, because each shares the 185 base pair fragment

No suspect matches, because the fragments are different lengths from each other

CRISPR can only be used on bacteria, so it cannot work in human embryos

Edits would be inherited by future generations who cannot consent to them

Edited genes cannot be passed on to any children born after the treatment

The technique is used only for forensic DNA profiling, not for treatment

5 percent

20 percent

25 percent

125 percent

It is not supported because the bean plants grew at all five temperatures

It is too specific, since it names one temperature instead of a range

It is invalid because temperature cannot be used as an independent variable

It generalises beyond the evidence, which came from a single species of plant