Chapter 21.2, Problem 7MI

Summary Introduction

To compare:

The characteristics of bryophytes, hepaticophytes, and anthocerophytes by completing the given table

Introduction: Plant kingdom can be classified into vascular and nonvascular plants. Vascular plants can be further classified as seedless and seed plants. Nonvascular plants lack conducting tissues and include bryophytes, hepaticophytes, and anthocerophytes.

Answer to Problem 7MI

	Description	Environment	Example
Bryophyta	Small plants with no true leaves but have structures similar to leaves, and have root like rhizoids.	Damp log, along a stream	Mosses
Hepaticophyta	Either thallose or leafy. Thallose have fleshy lobed structure and leafy ones have stems with leaf like structures. Unicellular rhizoids are also present.	Variety of habitats from tropics to the arctic, moist conditions such as damp soil, near water	Liverworts
Anthocerophyta	Thallose body, horn like sporophyte	Moist conditions	Hornworts

Explanation of Solution

Bryophyta- This division consists of mosses. They are small nonvascular plants growing on damp logs and alongside streams. They lack true leaves but have leaf like structures which can perform photosynthesis. They produce multicellular root like structures called rhizoids. Some mosses have stems that grow upright and others have trailing vine like stems.

Hepaticophyta- This division includes liverworts and has more than 6000 species. They are found in variety of habitats ranging from tropics to the arctic region. They grow close to ground and where moisture is available in plenty. Liverworts are classified as either thallose or leafy. A thallose liverwort has a body that resembles a fleshy lobed structure. Leafy liverworts have stems with flat, thin leaf like structures arranged in three rows. They also have unicellular rhizoids unlike multicellular rhizoids of bryophytes.

Anthocerophyta- It forms the smallest division of nonvascular plants. They are called hornworts because of horn like sporophytes. Only 100 species of hornworts are known. One large chloroplast is present in each cell of these plants. Besides the chloroplast in each cell the spaces around the cell is filled with slime instead of air. Nostoc often grows in this slime.