24.1 Reproduction in Flowering Plants

Key Questions

  • What are flowers?

  • How does fertilization in angiosperms differ from fertilization in other plants?

  • What is vegetative reproduction?

Vocabulary

stamen • anther • carpel • stigma • pistil • embryo sac • double fertilization • endosperm • vegetative reproduction • grafting

Taking Notes

Two-Column Table Construct a two-column table with the headings, Male Gametophyte and Female Gametophyte. As you read, take notes on the characteristics of each type of gametophyte.

THINK ABOUT IT about it What makes a flower beautiful? The symmetry of its petals, its rich colors, and, sometimes, its fragrance. But, at the heart of it, what's behind all this beauty? The answer is, simply, angiosperm sexual reproduction. To a plant, the whole point of a flower is to bring gametes together for reproduction and to protect the resulting zygote and embryo.

The Structure of Flowers

What are flowers?

You may think of flowers as decorative objects that brighten our world, and so they are. However, the presence of so many flowers in the world is visible evidence of something else—the stunning evolutionary success of the angiosperms, or flowering plants. The structure of a typical angiosperm flower is shown in Figure 24–1. Flowers are reproductive organs that are composed of four different kinds of specialized leaves: sepals, petals, stamens, and carpels.

Sepals and Petals The outermost circle of floral parts contains the sepals (SEE pulz). In many plants, the sepals are green and closely resemble ordinary leaves. Sepals enclose the bud before it opens, and they protect the flower while it is developing. Petals, which are often brightly colored, are found just inside the sepals. The colors, number, and shapes of such petals attract insects and other pollinators to the flower.

A diagram showing parts of flower which include Ovary, Ovule, Sepal, Petal, Stigma, Style, Anther and Filament.

FIGURE 24–1 The Parts of a Flower This diagram shows the parts of a typical flower. The flowers of some angiosperm species, however, do not have all the parts shown here.

End ofPage 696

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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