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Explore This Topic

Check Your Understanding

The following questions accompany this lesson. The answers are given below each question. To reveal an answer, place the cursor over "REVEAL THE ANSWER".

1. What are the three basic types of sensory receptors, and what type of information do they gather from the environment?
   

2. Dr. Zuker looked for molecules important in mechanoreceptor function by identifying fruit fly mutants with balance and coordination problems. Some flies, with mutations in single genes, have problems so severe that they can barely move. Since these flies would have difficulty mating, how is Dr. Zuker able to raise them in his laboratory?
   

3. Dogs have more limited color vision than humans, but are fairly adept at seeing at night. What might be the difference between a dog eye and a human eye that would cause this characteristic.
   

4. Some pigments play a very important role in nature. What are some similarities and differences between the function of the following pigments: chlorophyll, carotenoids and rhodopsin?
   

5. What possible receptor problem may cause colorblindness?
   

6. How does the structure of photoreceptors, mechanoreceptors and chemorececeptors facilitate their function?
   

7. Pheromones are chemicals released by an animal that transmit messages to other animals. Pheromones in humans are believed to be linked to sexual attraction. These pheromones travel through the air to receptors in the vomeronasal organ, an organ that is thought to be located between the nose and the mouth. What type of receptor do you think pheromone receptors are, and how do you think they might work?
   

Exercise Your Brain

1. View the video "Sweaty T-Shirts and Human Mate Choice." Why might pheromones and pheromone receptors have developed through evolution? Can you think of other ways the body sends and receives signals to and from others?

2. Discovering the molecule that carries out a specific duty within a cell can be very difficult, since molecules are quite small, and cells contain millions of them. Dr. Zuker's research has focused on identifying specific receptor molecules within the sensory neurons. In order to pinpoint these molecules, Dr. Zuker used genetic mutants. Choose one of the three senses studied by Dr. Zuker (1. vision, 2. taste, 3. mechanosenses--touch, hearing, balance), and describe specifically how he designed an experiment that identified one molecule and its role in the cell.

3. Brainstorm other receptors and senses found in humans and other animals, then compare your answers with a neighbor. Research and describe one of the following three sensory systems found in animals. How would you design an experiment to identify a specific receptor molecule in any of the following systems?
   Changes in water pressure, changes in electrical current
   Changes in infrared radiation/warmth