Chapter 21, Problem 3A

Summary Introduction

To write: The vocabulary term that match each phrase.

Introduction: Plants are vital to our survival. The oxygen we breathe, the food we eat, and many of the things that make our lives comfortable, such as clothing, furniture, and our homes, come from or are parts of plants.

Explanation of Solution

The oxygen and carbon dioxide exchange in the leaf happens through pores called stomata. As the sun hits the leaf in the morning, the stomata usually open and close throughout the night. The immediate cause is a variation in the guard cell turgor. Each Guard cell's inner wall is dense and elastic. As turgor forms within the two guard cells that flanked each stoma, the thin outer walls gush out and pull the inner walls into a crescent shape. This leaves the stoma open. The elastic inner walls recover their original form as the guard cells lack turgor, and the stoma shuts.

Conclusion

The exchange of gases in leaves takes place through pores known as stomata. As the sun hits the leaf in the morning, the stomata usually open and close throughout the night.