Many teachers and students had suggested that Chapters 35 (Genetic Transformation of Prokaryotes), 36 (Transgenic Animals), 37 (Transgenic Plants) and 38 (Biosafety) are better dealt in 'Biotechnology'. In deference to their wishes, these four chapters are not included in the fourth edition. In addition, the sequence of chapters has been reorganized to better reflect their interrelationships.
