EFFECT OF 0.1 mM CAFFEINE ON MEMORY IN BEES Treatment Memory (average probability of revisiting a nectar source +2SE2)
10 Minutes 24 Hours
Control 0.72± 0.09 0.41± 0.07
Caffeine 0.83 ± 0.07 0.78 ± 0.08
In flowering plants, pollination is a process that leads to the fertilization of an egg and the production of seeds. Some flowers attract pollinators, such as bees, using visual and chemical cues. When a bee visits a flower, in addition to transferring pollen, the bee can take nectar from the flower and use it to make honey for the colony. Nectar contains sugar, but certain plants also produce caffeine in the nectar. Caffeine is a bitter-tasting compound that can be toxic to insects at high concentrations. To investigate the role of caffeine in nectar, a group of researchers studied the effect of 0.1 mM caffeine on bee behavior. The results of an experiment to test the effect of caffeine on bees' memory of a nectar source are shown in Table.
a) Based on the table, describe the effect of caffeine on each of the following: 1) short-term (10 minute) memory of a nectar source and 2) long-term (24 hour) memory of a nectar source.
b) Design an experiment using artificial flowers to investigate potential negative effects increasing caffeine concentrations in nectar on the number of floral visits by bees. Identify the null hypothesis, an appropriate control treatment, and the predicted results that could be used to reject the null hypothesis.
c) Researchers found that nectar with caffeine tends to have a lower sugar content than nectar without caffeine. Plants use less energy to produce the caffeine in nectar than they do to produce the sugar in nectar. Propose ONE benefit to plants that produce nectar with caffeine and a lower sugar content. Propose ONE cost to bees that visit the flowers of plants that produce nectar with caffeine and a lower sugar content.