A green algae with haploid gametophyte, Mosses and relatives with larger gametophyte and smaller sporophytes, Ferns and relatives with small gametophyte and a larger sporophyte and Seed plants with even smaller gametophyte within sporophyte tissues.

FIGURE 22–6 Trends in Plant Evolution An important trend in plant evolution is the reduction in size of the gametophyte and the increasing size of the sporophyte. Interpret Visuals How does the relative size of the haploid and diploid stages differ between mosses and seed plants?

Figure 22–6 shows an important trend in plant evolution—the reduction in size of the gametophyte and the increasing size of the sporophyte. Although many green algae do have a diploid sporophyte phase, some do not; their only multicellular bodies are gametophytes. Mosses and their relatives consist of a relatively large gametophyte and smaller sporophytes. Ferns and their relatives have a small gametophyte and a larger sporophyte. Seed plants have an even smaller gametophyte, which is contained within sporophyte tissues.

22.1 Assessment

Review Key Concepts

    1. Review List the basic needs of a plant.

    2. Interpret Visuals Summarize how the plant shown in Figure 22–2 meets basic needs.

    1. Review How did the relative lack of water on land affect how plants evolved?

    2. Infer How might the adaptation of specialized water-conducting tissue have helped land plants meet challenges to life on land? Explain.

    1. Review Which phrase is used to describe a plant's life cycle?

    2. Compare and Contrast Compare the gametophyte and sporophyte stages of plant life cycles. Which stage is haploid? Which is diploid?

ANALYZING DATA

Use the circle graph in Figure 22–4 to answer the questions below.

  1. Calculate What percentage of all plants are flowering plants?

  2. Interpret Graphs What is the second largest group of plants?

  3. Pose Questions What question about plant evolution would you ask based on the data in this graph?

End ofPage 638

Table of Contents

Miller & Levine Biology
About the Authors
Changing the World of Biology Education
Contents
Diversity of Life: A Visual Guide DOL•1–DOL•64
Labs and Activities
Features
UNIT 1 The Nature of Life
1 The Science of Biology
2 The Chemistry of Life
Unit Project
UNIT 2 Ecology
3 The Biosphere
4 Ecosystems and Communities
5 Populations
6 Humans in the Biosphere
Unit Project
UNIT 3 Cells
7 Cell Structure and Function
8 Photosynthesis
9 Cellular Respiration and Fermentation
10 Cell Growth and Division
Unit Project
UNIT 4 Genetics
11 Introduction to Genetics
12 DNA
13 RNA and Protein Synthesis
14 Human Heredity
15 Genetic Engineering
Unit Project
UNIT 5 Evolution
16 Darwin's Theory of Evolution
17 Evolution of Populations
18 Classification
19 History of Life
Unit Project
UNIT 6 From Microorganisms to Plants
20 Viruses and Prokaryotes
21 Protists and Fungi
22 Introduction to Plants
23 Plant Structure and Function
24 Plant Reproduction and Response
Unit Project
UNIT 7 Animals
25 Introduction to Animals
26 Animal Evolution and Diversity
27 Animal Systems I
28 Animal Systems II
29 Animal Behavior
Unit Project
UNIT 8 The Human Body
30 Digestive and Excretory Systems
31 Nervous System
32 Skeletal, Muscular, and Integumentary Systems
33 Circulatory and Respiratory Systems
34 Endocrine and Reproductive Systems
35 Immune System and Disease
Unit Project
A Visual Guide to The Diversity of Life
HOW TO USE THIS GUIDE
THE TREE OF LIFE
Bacteria
Protists
Fungi
Plants
Animals
Appendices
Appendix A Science Skills
Appendix B Lab Skills
Appendix C Technology & Design
Appendix D Math Skills
Appendix E Periodic Table
Glossary
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q, R
S
T
U
V
W
X, Y, Z
Index
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
W
X
Y
Z
Credits
Go to previous page Go to next page