10.4 Cell Differentiation

Key Questions

  • How do cells become specialized for different functions?

  • What are stem cells?

  • What are some possible benefits and issues associated with stem cell research?

Vocabulary

embryo • differentiation • totipotent • blastocyst • pluripotent • stem cell • multipotent

Taking Notes

Compare/Contrast Table As you read, create a table comparing the ability of different cell types to differentiate.

THINK ABOUT IT The human body contains an estimated 100,000,000,000,000 (one hundred trillion) cells. That's a staggering number, but in one respect it's not quite as large as you might think. Why? Try to estimate how many times a single cell would have to divide through mitosis to produce that many cells. It may surprise you to learn that as few as 47 rounds of cell division can produce that many cells.

The results of those 47 cell cycles are truly amazing. The human body contains hundreds of distinctly different cell types, and every one of them develops from the single cell that starts the process. How do the cells get to be so different from each other?

From One Cell to Many

How do cells become specialized for different functions?

Each of us started life as just one cell. So, for that matter, did your pet dog, an earthworm, and the petunia on the windowsill. These living things pass through a developmental stage called an embryo, from which the adult organism is gradually produced. During the development process, an organism's cells become more and more differentiated and specialized for particular functions. Figure 10–18 shows some of the specialized cells found in the roots, stems, and leaves of a plant.

An illustration of specialized plant cells shows: Cells that store sugar, Cells that transport materials, and Cells that carry out photosynthesis.

FIGURE 10–18 Specialized Plant Cells

End ofPage 292

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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