Chapter 36, Problem 36.1CR

How did the evolution of xylem and phloem contribute to the successful colonization of land by vascular plants?

Summary Introduction

To determine: The way in which the evolution of xylem and phloem contributes to the successful colonization of land by vascular plants.

Introduction: Vascular plants are also called tracheophytes that use specialized tissue (xylem and phloem) for transporting food and water to different plant parts.

Explanation of Solution

As a result of selection pressure for plants with tall shoots, the separation of leaves from roots occurs. The problem of transport of material was created by this separation. Vascular system performs the essential function of transportation by delivery of resources, such as nutrients, water, and sugars to the various organs of the plants.

Xylem and phloem are the two main vascular tissues that consist of long narrow cells arranged end to end forming a tube-like structure. Xylem carries water and dissolved minerals from roots to the leaves and stems. Phloem transports food like sugar dissolved in water from photosynthetic cells to the other parts of plants like fruits for the growth and storage. Along with transportation, vascular system helps in long distance communication, physiological, and in defense-related processes.