Chapter 22, Problem 9STP

Summary Introduction

To write:

The word or phrase that describe the branching points A and B in the diagram.

Introduction:

The diversity of plants and its classification depends on adaptation. The plants are classified into twelve divisions. These twelve divisions of plants are divided into two groups; the non-vascular plants and the vascular plants. The non-vascular plants have lack of specialized transport tissue while the vascular plants have specialized transport tissue.

Explanation of Solution

In the evolutionary tree, A represents strobilus. Strobilus is a cluster of spore form a compact structure. The club moss has strobilus. The point B is represented as rhizome, that means the ferns in its sporophytic phase form root and underground stem which is termed as rhizome.

Conclusion

A represents strobilus, a cluster structure of spore and B represents rhizome.