The 21st century has been called the century of life science. The DNA double-helix model published in 1953 by J. Watson and F. Crick greatly contributed to and influenced the advancement of life science by showing how genes produce proteins that constitute the bodies of organisms and how genes are copied. Additionally, decoding of the genomes (i.e., the full sets of genetic information) of various organisms, which has been ongoing since the late 20th century, has significantly influenced not only fields related to life science but also the nature of humans and other organisms, as well as the way we view ourselves and other life forms. In this way, our knowledge of life science has continued to increase at an explosive rate since the 20th century; this knowledge is deeply associated not only with life science fields but also with natural science as a whole, and influences a variety of fields including human and social sciences. Today, knowledge of life science is increasingly required in a wide range of disciplines.
On the other hand, an education initiative in the Japanese elementary and secondary education system called “education with latitude” has reduced the number of learning targets for students, resulting in a situation where education provided in the country cannot sufficiently deal with scientific advancement and the increased amounts of information that have resulted. Accordingly, at the University of Tokyo’s College of Arts and Sciences, first- and second-year students in Science Stream II (mainly scientific, agricultural and pharmaceutical majors) and Science Stream III (medical majors) have traditionally been obliged to take Life Science as part of their studies. However, since FY 2006, the subject has also been compulsory for students in Science Stream I (mainly science and engineering majors). This is a message from the University of Tokyo that all students of science-related majors, including science and engineering courses, should learn the basics of modern life science.
The editing of this Life Science book began against such a background, and extensive discussions were held to decide the perspectives and details of life science to be taught to new Science Stream I students, many of whom chose physics and chemistry for their university entrance examinations and therefore have scant knowledge of biology (life science). This is because, as mentioned above, vast amounts of information have been accumulated in the area of life science, which has undergone great expansion as an academic field. Specifically, the various areas of life science constitute a vertical axis from macro to micro fields, including global ecology and environmental sciences, the diversity and evolution of organisms, structural biology, biochemistry, physiology, developmental biology, cell biology, neuroscience, molecular biology, bioinformatics (i.e., the fusion of life science and information science) and genome biology. Based on discussions to decide the core of life science learning, we decided to compile a book that first deals with the concept of cells - the basic units of organisms - and subsequently expands to cover fields along the horizontal axis. This axis was then established by proceeding from cell structure (i.e., the nature of cells) to the organelles that constitute cells, molecules such as DNA and proteins, the mechanism of information transfer from external to internal cell environments, the mechanism of intercellular communication, development and differentiation, and reproduction. This is designed to help students learn the basics of life science through the interwoven patterns of the vertical and horizontal axes.
This textbook was designed to enable completion in a single semester (12 - 13 classes), and therefore consists of 12 chapters. Each begins with a short section introducing the main points of the chapter, followed by the main text. Advanced information and new knowledge are provided separately in Columns. A summary, including the contents of the Columns, is then provided at the end of each chapter. With regard to the basics of life science, the layout and editing have been finalized in a way that promotes student understanding by placing essential information first followed by other items.
As mentioned above, vast amounts of knowledge have been accumulated, and information continues to be added every year in the field of life science, which has expanded from the molecular level to individual and societal levels. For science and engineering students, life science is about understanding ourselves - humans - as well as learning about the commonality and uniqueness of the approximately 10 million species that inhabit the earth, including us. We believe that a knowledge of the mechanisms, the fascination and the beauty of life-related phenomena will be greatly beneficial to students regardless of the future courses they pursue. As it is not possible to cover everything due to page and class-hour limitations, this publication deals with basic knowledge centering on cells. We hope that this Life Science book will give as many students as possible a sense of the extent and depth of this academic field. We also hope that it will become a standard text for life science classes on general education courses for science and engineering majors. This book was edited and revised by the University of Tokyo Network for Life Science Education, the University of Tokyo College of Arts and Sciences Biology Group and the University of Tokyo Center for Structuring Life Sciences. In revising its contents, tasks have been added to each chapter to aid student understanding. It is our hope that this publication will help to bridge the gap between general and specialized courses.
Early spring 2008