Chapter 21, Problem 33A

Summary Introduction

To write:

The adaptive advantage of having a gametophyte dependent on a sporophyte.

Introduction:

Vascular seed plants produce seeds. Each seed contains a tiny sporophyte surrounded by a protective tissue. Plants whose seeds are part of fruits are called angiosperms and those plants that do not bear fruits are called gymnosperms.

Explanation of Solution

The sporophyte is dominant in seed plants and produces spores. Spores divide to form the male and female gametophytes by meiosis. Each female gametophyte is made up of one or more eggs enclosed by protective tissues. Most seed plants do not require water for reproduction. This adaptation enables seed plants to thrive in different environments, including areas where water is scarce. This allows them to display their large, long-lived sporophyte phase as the actual plant and allows the plants to produce fruits and reproduce. Thus, it completes the lifecycle of plants.

Conclusion

The sporophyte is made of the entire body of the plants in seed bearing plants, except for the embryo sac and pollen.