Quick Lab
GUIDED INQUIRY

What Is the Structure of a Flower?

  1. Examine a flower carefully. Make a detailed drawing of the flower and label as many parts as you can. Note whether the anthers are above or below the stigma.

  2. Remove an anther and place it on a slide. While holding the anther with forceps, use the scalpel to cut one or more thin slices across the anther. CAUTION: Be careful with sharp tools. Place the slide on a flat surface before you start cutting.

  3. Lay the slices flat on the microscope slide and add a drop of water and a coverslip. Observe the slices with the microscope at low power. Make a labeled drawing of your observations.

  4. Repeat steps 2 and 3 with the ovary.

    Analyze and Conclude

  1. Observe Are the anthers in this flower located above or below the stigma? How could this affect what happens to the pollen produced by the anthers? Explain your answer.

    Palms holding an Anther on slide with forceps and cutting it with scalpel.

  2. Apply Concepts What structures did you identify in the anther? What is the function of these structures?

  3. Apply Concepts What structures did you identify in the ovary? What is the function of these structures?

  4. Draw Conclusions Which parts of the flower will become the seeds? Which parts will become the fruit?

The Angiosperm Life Cycle

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

Like other plants, angiosperms have a life cycle that shows an alternation of generations between a diploid sporophyte phase and a haploid gametophyte stage. Recall that in vascular plants, including ferns and gymnosperms, the sporophyte plant is much larger than the gametophyte. This trend continues in angiosperms, where male and female gametophytes live within the tissues of the sporophyte.

Development of Male Gametophytes The male gametophytes—the pollen grains—develop inside anthers. This process is shown in the top half of Figure 24–3. First, meiosis produces four haploid spore cells. Each spore undergoes one mitotic division to produce the two haploid nuclei of a single pollen grain. The two nuclei are surrounded by a thick wall that protects the male gametophyte from dryness and damage when it is released. The pollen grains stop growing until they are released from the anther and land on a stigma.

In Your Notebook Make a flowchart that records the stages of development of an angiosperm's male gametophyte.

End ofPage 698

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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