Example of Science Lesson Plan-Human Senses
Students will understand the following:
- The brain links our sense of taste with our sense of smell.
- The tongue can determine only four basic tastes: salty, sour, bitter, and sweet.
- All the more subtle tastes we experience are largely a function of olfactory senses, or smell.
Each group will need the following materials:
- Variety of substances to taste, including raw onion and raw potato
- Prepared list of the substances to be tasted (copy for each student)
- Ask your students if they are certain that they could distinguish a slice of raw potato from a slice of raw onion in a blindfolded taste test. Then ask them if they could distinguish between the two tastes while blindfoldedandholding their noses.
- Tell students they are going to perform a test to find out if their predictions were correct and then discuss the reasons for the results.
- Have students form two groups. One group will hold their noses while blindfolded and taste various substances, including raw potato and raw onion. The other group will taste the same substances while merely blindfolded.
- Have each student from one group, then the other, take the taste test. Instruct students to try to identify each substance but to say, 'I don't know,' if they have no idea what the substance is. As each student takes the test, check off on his or her list which substances are correctly identified, which are incorrectly identified, and which get an 'I don't know.' (You may prefer to appoint students to administer the tests.)
- Appoint a small group of students to compile the results of the test. How many correct identifications of each substance were made by students holding their noses compared with the number of correct identifications made by students able to smell?
- Discuss the results with the class, leading students to infer that smell and taste are linked.
- Encourage students to do further research on the relationship between smell and taste, or explain to them that the tongue can distinguish only four basic tastes-salty, sour, bitter, and sweet. All the more subtle tastes we experience are largely a function of our sense of smell.
- Have each student write a paragraph describing the experiment and his or her own personal experience while taking the test.
Ask these questions to your students:
- Compare the brain's coordination of depth perception and location of sound.
- Describe how olfactory impairment (even holding one's nose) could affect taste perception.
- Discuss how technology has improved our ability to perceive ourselves.
- Discuss how experiences, emotions and cultural patterns affect people's perceptions, and how perceptions may affect a culture. How might this explain the existence of certain prejudices?