Learning engagement 3: Scenarios for discussing the guidelines for the use of animals in IB World Schools
• We will consider each scenario in relation to the IB experimental guidelines (in the TSM) on ethics and safety.
• Please consider each scenario as a suggestion from a pupil who will need advice in terms of safety, risk
assessment and ethics, as applicable.
• Each pair will research certain scenario and offer their findings to the whole group.
• Comments on the feasibility of the investigation are also welcome.
DP biology investigation suggestions
1. A student wants to investigate the effect of different pH levels on the growth of Penicillium. He will
cut wells into 6 nutrient agar plates and then seed the plates with Penicillium fungus spore wash. He
then plans to fill the 6 pre-cut wells with buffer solutions at pH levels ranging from pH2 to pH12 and
incubate the agar plates at 37 degrees Celsius for 3 days before recording the results. He intends to
measure the diameter of the cleared areas around each well (zone of inhibition) and compare
clearance at different pH levels.
2. A student has planned an experiment to test the effect of salty food on human urine production by
collecting urine produced per hour for a four-hour period after salt ingestion. Her idea is that urine
production is inversely proportional to the salt consumed. The salt was delivered through a range of
crisp products chosen for their salt content. The crisps range from no added salt to super salty. The
actual mass of added salt is available on the pack.
3. A range of drosophila (fruit flies) can be bought from a local laboratory supplier to investigate
genetic crosses. The student decided on the strains she wished to cross to examine certain features to
compare observed and expected Mendelian ratios in the F1 generation.
4. A student has decided to investigate the effect of detergents on the conjunctiva. She has obtained
data from an extensive data base published by a pharmaceutical company developing cleaning
products in the 1960s. The data gives the results of tests performed on 100 adult rabbits. The rabbits
were given a 10 second eyebath containing a 1 in 10 dilution of the detergent. The results record the
redness in the rabbits’ eyes using percentage coverage and the time taken (in days) for spontaneous
recovery (without the use of medication).
5. A group of four students are investigating reaction times in relationship to background noise. They
decided to use software that records the time taken to react to a traffic light using the space bar on a
computer keyboard whilst being exposed to rock music at different decibel levels.
6. A student has decided to carry out frog dissections to demonstrate the structure of the heart. There is
a pond within the school grounds so he plans to collect the frog spawn and allow the resulting
tadpoles to mature into frogs. A total of 10 frogs will be used for dissection, the remainder returned to
the pond. He has extensively researched the best way to kill the frogs prior to dissection and has made
a work sheet to show how to pith the frog (a method used to render a frog senseless).
7. A student would like to investigate the effect of caffeine on heart rate. They propose to allow 10 of
their fellow students to drink different strengths of ground coffee and then measure the heart rate
before and after consumption.
8. A group of students have used garden snails (Cornu aspersum) to investigate photokinesis. The
snails were placed in the dark and then subjected to a range of light intensities and their rate of
withdrawal into their shells was to be recorded.
9. On a field trip in a protected wetland, a student has decided to test whether the body length of
caddisfly cases is related to the oxygen level of the water. She will collect 20 specimens from each of
3 areas in the wetland and measure their case length and width. She will use a probe to measure the
oxygen level of the water.
10. “Is there a relationship between fighting fish breathing rate and the temperature of the water of the
aquarium?” The student has several pet fighting fish in fish bowls and plans to measure operculum
movements at various temperatures.
11. A pupil would like to investigate the effect of drying on bacterial growth from human mouths on
toothbrushes. The toothbrush will be used by the pupil and then left in air after brushing the teeth.
Samples will be taken for plating every 30 minutes after brushing for 5 hours.
