Unit 4 The Sense of Smell

Content Learning Goal We will learn three parts of the nose and how the nose is used to tell us about things.

Language Learning Goal Define: Odor Molecules Nostrils Olfactory nerves

Smells tell about things How can you know what is for dinner before you even see it or taste it? Sometimes we SMELL the odor or aroma of food and know what we’ll be eating. The sense organ that makes this possible is the NOSE.

Travelers Light rays travel through the eyes so we can see. Sound waves travel through the ear so we can hear. Noses work this way too…molecules travel through the nose so we can smell. Molecules are tiny pieces of a thing that float in the air. When we breathe in the air, the molecules go into our noses and we smell the odors of things.

How the Sense of Smell Works What happens when an odor reaches the nose? Look at the diagram on Pages 168-169. It shows the parts of the nose. Answer questions 1, 2 & 3 on Page 169 about what happens when we smell an odor.

Experiment 4 Read Page 170 and prepare for Experiment 4. You’ll need a bottle of perfume and a watch with a second hand. Once you are finished, complete the Observation and Conclusion questions on Page 171.

Review Complete questions 1-6 on Page 172.

Bonus Questions What is your favorite smell? What is your least favorite smell?