Taste and Smell

Free Response

From the perspective of the recipient of the signal, in what ways do pheromones differ from other odorants?

Hint:

Pheromones may not be consciously perceived, and pheromones can have direct physiological and behavioral effects on their recipients.

What might be the effect on an animal of not being able to perceive taste?

Hint:

The animal might not be able to recognize the differences in food sources and thus might not be able to discriminate between spoiled food and safe food or between foods that contain necessary nutrients, such as proteins, and foods that do not.

A few recent cancer detection studies have used trained dogs to detect lung cancer in urine samples. What is the hypothesis behind this study? Why are dogs a better choice of detectors in this study than humans?

Hint:

These studies rely on the dogs’ olfactory senses. The hypothesis behind the study is that the dogs are capable of detecting volatile compounds (evaporating scent molecules) that are only produced in people with cancer. The dogs are a better choice because their sense of smell is more sensitive due to the increased number of olfactory receptors.