The Facts On File Illustrated Guide To The Human Body: Cells and Genetics

113 Pages·2005·11.03 MB·English

by  Facts on File

THE FACTS ON FILE
ILLUSTRATED GUIDE TO
THE HUMAN BODY
CELLS AND
GENETICS
THE DIAGRAM GROUP
The Facts On File Illustrated Guide to the Human Body:
Cells and Genetics
Copyright © 2005 The Diagram Group
Editorial: Lionel Bender, David Harding, Tom Jackson
Denis Kennedy, GordonLee, Jamie Stokes
Scientific consultant: Stephen Rudd
Design: Anthony Atherton, Richard Hummerstone,
Lee Lawrence, Kim Richardson, Ben White
Illustration: Pavel Kostal, Kathleen McDougall
Picture research: Neil McKenna
Indexer: Jane Parker
All rights reserved. No part of this book may be reproduced or
utilized in any form or by any means, electronic or mechanical,
including photocopying, recording, or by any information storage or
retrieval systems, without permission in writing from the publisher.
For information contact:
Facts On File, Inc.
132 West 31st Street
New York NY 10001
Library of Congress Cataloging-in-Publication Data
The Facts On File illustrated guide to the human body. Cells and
Note to the reader
genetics / the Diagram Group.
p. cm. This book is not intended
Includes index. to serve as a medical
ISBN 0-8160-5980-2 (hc : alk. paper) textbook for either
1. Cytology—Juvenile literature. 2. Human genetics—Juvenile
physicians or patients.
literature. I. Title: Illustrated guide to the human body. Cells and
The information and
genetics. II. Title: Cells and genetics. III. Diagram Group.
QH582.5.F33 2005 advice it contains should
611’.0181—dc22 not be used or relied upon
2004026104 without consulting the
Set ISBN: 0-8160-5979-9
advice of a qualified
physician. The publishers
Facts On File books are available at special discounts when
purchased in bulk quantities for businesses, associations, disclaim any responsibility
institutions, or sales promotions. Please call our Special Sales for the accuracy of the
Department in New York at 212/967-8800 or 800/322-8755. information or advice
that this book contains
You can find Facts On File on the World Wide Web at
and any responsibility for
http://www.factsonfile.com
any consequences that
Printed in the United States of America may result from any use or
reliance thereon by
EB Diagram 10 9 8 7 6 5 4 3 2 1
the reader.
This book is printed on acid-free paper.
Contents
Introduction:About this book 4
SECTION1 Cell death 62
CELL STRUCTURE Cancer cells 64
Introduction 6
Cells, tissues, and organs 8 SECTION4
Cell membrane 10 CHROMOSOMES
Cytoplasm 12 Introduction 66
Cytoskeleton 14 Chromosome number and function 68
Endoplasmic reticulum 16 Alleles 70
Ribosomes 18 DNA structure 72
Golgi apparatus 20 DNA function 74
Nucleus 22 Genes and gene expression 76
Lysosomes 24 DNA replication 78
Mitochondria 26 DNA repair 80
Other organelles 28 Mutations in DNA 82
Intercellular junctions 30 Chromosomal changes 84
Cilia and flagella 32
Extracellular matrix 34 SECTION5
HEREDITY
SECTION2 Introduction 86
HOW CELLS WORK How inheritance works 88
Introduction 36 Sex determination 90
Diffusion and osmosis 38 Genetic disorders 92
Active transport 40 Chromosomal disorders 94
Membrane potentials 42 Genes and cancer 96
ATP and cellular respiration 44 Genetic testing 98
Protein synthesis 46 Gene therapy 100
Cell signaling 48
Types of cells 50
Glossary of the human body 102
SECTION3 Web sites to visit 108
CELL LIFE CYCLE Index 109
Introduction 52
Controlling the cell cycle 54
Mitosis 56
Meiosis 58
Stem cells and specialization 60
Introduction
4
This book is a concise, illustrated guide to the There are five sections within the book. The
anatomy, physiology, well-being, and first section looks in detail at the microscopic
disorders of human cells, chromosomes, and structure of human body cells. The second
genes. It has been written and illustrated section describes and illustrates the chemical
specially for students and laypeople interested processes that take place within these cells.
in cell biology, medicine, health, and hygiene. Section 3 focuses on cell growth and division.
The subject is dealt with in clear steps, so that Section 4 deals with the structure and
the reader can steadily acquire a good overall function of chromosomes, the genetic
understanding. Explanatory texts, diagrams, material within cells. Section 5 looks at
illustrations, captions, and fact boxes are the processes and outcomes of heredity and
combined to help readers grasp important inheritance. Within sections 3 and 4,
information at a glance. A glossary of discussion and illustration of the structure
scientific and jargon words defines medical and function of the cell components are
terms in everyday language. A list of Web sites followed by principles of cell disorders.
provides links to other relevant sources of Section 5 looks at medical advances in
information, and the index enables quick genetics. Information is presented as double-
access to articles. page topics arranged in subsections.
Human body systems
This book is one of eight
titles in THE FACTS ON
FILE ILLUSTRATED
GUIDE TO THE HUMAN
BODY series, which looks
at each of the major body
systems in turn. Some
of the titles in the series
include more than one
system. The skeletal and
muscular systems, and
the blood and lymphatic
systems, for example,
work in conjunction and
so are treated together.
There is a separate title
for human cells and
genetics, which are the
building blocks and
underlying chemistry of Skeletal and Brain and Heart and
all body systems. Muscular Systems Nervous System Circulatory System
ABOUT THIS BOOK
5
Section 1: CELL STRUCTURE explores the Section 5: HEREDITY summarizes the
organization and internal structure of cells, processes of inheritance and reveals how
looking at each organelle in turn. changes to genes at the molecular level
Section 2: HOW CELLS WORK focuses on influence large-scale metabolic and physical
cell “biochemistry,” the chemical processes of characteristics.
living material.
Section 3: CELL LIFE CYCLE looks at the This book has been written by anatomy,
stages of cell growth, division, and physiology, and health experts for non-
multiplication. It also describes how non- specialists. It can be used:
specific “stem” cells give rise to colonies of • as a general guide to the way the human
specialized body cells. body functions
Section 4: CHROMOSOMES features the • as a reference resource of images and text
body’s genetic blueprint, surveyed at the for use in schools, libraries, or in the home
molecular level. It also looks in detail at the • as a basis for examination preparation for
double-helix structure and functioning of students of human biology, medicine,
deoxyribonucleic acid (DNA). nursing, physiotherapy, and general
healthcare.
Digestive The Senses Respiratory Reproductive Cells and M
A
System System System Genetics GR
A
DI
©
Introduction
6
There are many different types of human cells, for
Cell facts
example, blood cells, nerve cells, and muscle cells. Each
• A cell’s organelles are
cell type has a structure adapted to perform particular
surrounded by a liquid
tasks. However, all human cells (and those of other
called cytoplasm.
animals) share a similar basic structure and contain • Mitochondria release
a range of internal structures known as organelles. energy from food.
Human cells even share features with plant cells.
Basic cell structure
• The cell is surrounded by a narrow DNA and are only clearly visible just
fatty layer called the cell or plasma before and during cell division.
membrane. • The cytoplasm, a gel-like fluid,
• The nucleus is the cell’s control center surrounds the nucleus.
containing its DNA. • Organelles are suspended in the
• The nuclear membrane is another fatty cytoplasm. Each organelle has a
layer that encases the nucleus. particular job.
• Chromosomes are bar-like structures • Centrioles are a pair of rod-shaped
found inside the nucleus. They hold the organelles involved in cell division.
Basic cell structure Plasma membrane
●
Cytoplasm
●
Mitochondrion
●
Golgi apparatus
Endoplasmic reticulum ●
●
Centriole
●
Nuclear membrane
●
Ribosome
● Nucleus
●
●
Lysosome
Vacuole
●
SECTION 1: CELL STRUCTURE
7
Cellular scale
Cellular scale A micron, or micrometer Human cells come in
(µm) is 1 millionth of a a wide range of sizes.
meter, or 1⁄2500inch. A human egg cell (ovum)
is comparatively large.
At 300 µm in diameter, it is
just about visible to the
naked eye. Most other
300 µm human egg cell
cells in the body are a
fraction of this size.
The cells that line the
stomach are relatively
large. Like skin cells, these
are gradually shed. Muscle
10 µm stomach wall cell fibers, or myofibrils, would
at first glance appear to be
the largest body cells
since they can be anything
from 1 mm to almost
3 cm long. However,
1–30 mm muscle cells although these fibers are
bound by a single cell
membrane, they are not
really a single cell since
they are multinucleated—
they may contain many
7.5 µm red blood cell thousands of nuclei each.
Red blood cells are at the
smaller end of human
cells. They lack many of
the internal features of
other cells.
Single-celled organisms,
5 µm yeast cell
such as yeast (a fungus)
and bacteria tend to be
small. It would take about
500 bacteria, each 1.5 µm
long, to cover the period
1.5 µm E. coli bacterium at the end of this sentence. AM
R
G
A
DI
©
Cells, tissues, and organs
8
Levels of organization
Structures of the body
The body is a single organism (living
creature) made up of many different
substances and structures. These can
1
be arranged into levels of increasing
complexity called levels of organization,
beginning with the most basic.
Atoms
1 Biochemistry: atoms and molecules Molecule
make the substances that are the
building blocks (for example, water
and protein) of all the other levels.
2 Cells are the smallest living units
of the body. 2
3 Tissues are formed by groups
of cells with similar structures and
Cell
functions (together with other ●
substances).
4 Organs are formed by tissues.
5 Body systems result from various
organs working together and Stomach
3
include, for example, the digestive linings
●
system.
6 The body (organism)
is the sum of all the
levels existing and
operating together. Body
●
4
Digestive
system Stomach
● ●
6 5
SECTION 1: CELL STRUCTURE
9
Cells, tissues, and organs
It is estimated that the human body
contains about 100 trillion cells. These
are specialized to perform certain
functions and have a wide variety of
Flat layer of cells
shapes and sizes. They are organized
into separate structures within the body.
Tissues
Cells of the same type are organized
into layers or other types of groupings
known as tissues.
The cells in tissues are devoted to
a narrow range of functions. Examples
of tissues include:
Tubule
• cells arranged to form a thin layer
of tissue (epithelium) as found in
the lining of the mouth;
• cells forming a tubule (small tube)
as in a kidney tubule; and
• muscle cells arranged in a sheet of
muscle tissue, as occurs in the wall
of arterial blood vessels.
Blood vessels
Organs
Tissues of different kinds are themselves
grouped together to form the organs of
the body. These include the skin, heart,
liver, and kidneys. For example,
human skin contains several distinct
Skin
layers of tissue:
• a protective layer of dead cells (a)
a
to prevent infection, and drying out;
• epidermal cells (b), some of which
form the hair follicles;
b
• a basement membrane (c) separating
the epidermis from the dermis; and
• the dermis layer (d), which includes c
cells responsible for maintaining the
d
strength and integrity of the skin, as
well as sensory nerve endings, blood M
A
R
vessels, and muscle fibers. G
A
DI
©