Chapter U2.46, Problem 9E

Interpretation Introduction

Interpretation : It is useful for humans to be able to smell certain substances and not others. The reason for this is to be explained.

Concept Introduction :

Humans can smell different kinds of substances. Our nose is sensitive to many smells but still one cannot smell many substances.

Answer to Problem 9E

It is biologically advantageous for humans to be able to smell certain substances such as a gas leak or fumes from a fire. This can prevent us from accidents and prepare us for danger. Smells that are pleasant such as that of perfume or flowers make us happy. Smell from food makes us feel hungry and good.

Explanation of Solution

It is biologically advantageous for humans to be able to smell certain substances such as a gas leak or fumes from a fire. This can prevent us from accidents and prepare us for danger. One may be able to prevent accidents and escape from the site. Smell from things burning helps us to detect the fault and one can prevent accidents/ damage by switching off the appliance’s gas burners. Smells that are pleasant such as that of perfume or flowers make us happy. Smell from food makes us feel hungry and good.

Conclusion

Our nose is sensitive to variety of smells. Some smells are pleasant while some are unpleasant. One can smell variety of substances but it is not possible to smell each and every substance.