Life cycle of water mold is illustrated. It depicts how water molds can reproduce both sexually and asexually.

FIGURE 21–7 Water Mold Life Cycle Water molds reproduce both asexually and sexually.

d

The life cycle of a water mold is shown in Figure 21–7. Water molds grow into long branching filaments consisting of many cells formed by mitotic cell division. Water molds—and many other protists—reproduce asexually by producing spores in a structure called a sporangium (spoh RAN jee um). In water molds the spores are flagellated. Water molds also reproduce sexually by undergoing meiosis and forming male and female structures. These structures produce haploid nuclei that fuse during fertilization, forming a zygote that begins a new life cycle.

21.2 Assessment

Review Key Concepts

    1. Review Summarize three ways in which protists move.

    2. Compare and Contrast How is movement by means of flagella different from movement by means of cilia?

    1. Review Describe how protists reproduce.

    2. Explain How does conjugation produce genetic diversity in a population of Paramecium?

    3. Compare and Contrast How does a macronucleus differ in function from a micronucleus?

Apply the Big idea

Information and Heredity

  1. Compare asexual and sexual processes in paramecia. Include the terms mitosis and meiosis in your answer. You may want to refer back to Chapters 10 and 11 to review mitosis and meiosis.

End ofPage 609

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
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