- Bumblebees (Bombus terrestris) are insects that have both individual and social learning capacities. Scientists trained individual bumblebees to push either a blue tab or a red tab on a puzzle box to rotate the lid, exposing a reward consisting of a sucrose solution.
two diagrams of a puzzle box showing “sucrose hidden” with a red tab and a blue tab, and “sucrose exposed” with the lid rotated
Individual trained bumblebees were then mixed with untrained bumblebees to determine if the trained ones could teach the untrained ones how to expose the sucrose solution. All groups had the same number of bumblebees.
Experimental groups:
• B: 1 bumblebee trained to open the blue tab plus untrained bumblebees
• R: 1 bumblebee trained to open the red tab plus untrained bumblebees
• C (control): no trained bumblebees, only untrained bumblebees
The bumblebees in each group were allowed to try and open the puzzle box. Untrained bumblebees were considered to become “learners” when they opened the puzzle box twice.
line graph of number of learners per day (0–6) for groups B, R and C
(a) State the number of learners in the R group on day 6. [1]
(b) Compare and contrast the trends in the number of learners for the B group and R group over the course of the investigation. [2]
(c) Calculate the percentage increase in the number of learners in the R group between days 3 and 6. [1]
bar chart of total number of times the puzzle box was opened by groups B, R and C, split by red tab (grey) and blue tab (hatched), with magnified view of C
(d) Estimate the total number of times the puzzle box was opened using the red tab in the B group. [1]
(e) Using all the data provided, suggest with a reason which group is more efficient at opening the puzzle box. [1]
box‑and‑whisker plot of Learner Proficiency Index for group C and group B+R, outlier labeled “y12”
(f) Determine which percentage of the B+R group had an LPI of 28 or less. [1]
(g) (i) State the LPI for bumblebee y12. [1]
(ii) Calculate the number of days it took bumblebee y12 to become a learner. [1]
(h) Justify this conclusion using all the data provided. [3]