1 What is Selectivity? purpose, and crop protective agent for the A biologically-active substance is said to be second, but there is no fundamental difference selective if it strongly affects certain cells with of principle in their mode of action. out causing any change in others, even when the Drug therapy has two, fundamentally two kinds of cells are close neighbours. In living opposed divisions. The first of these strives to organisms, there are many substances, often improve the...

This book is about selectively toxic agents. That is to say, it is about those substances that affect certain cells without harming others, even when they are close neighbours. Toxicity need not be fatal. It can be made easily reversible, as is the case with general anaesthetics. Selective toxicity covers an immense field: most of the drugs used for treating illness in man and his economic animals, as well as all of the fungicides, insecticides, and weed killers that are used in agricultur...

Get your child excited about math with some maze fun. This book combines the study of math with the fun of games. Select a multiplication problem and solve it, then check your answer with the math maze. Explore the maze to arrive at the answer.Easily navigate the links to the math maze and answer. Then return to the practice problems to select another. Twenty problems in all, each with an answer maze. Most appropriate for 3rd and 4th grade students.

THE MAGIC SCHOOL BUS PRESENTS THE PLANETS is a photographic nonfiction companion book to the original bestselling title, THE MAGIC SCHOOL BUS LOST IN THE SOLAR SYSTEM.LOST IN THE SOLAR SYSTEM taught thousands of kids about the planets, moons, stars, and everything else you'd want to know about outer space. MAGIC SCHOOL BUS PRESENTS THE PLANETS will expand upon the original title with fresh, updated, Common Core aligned content about the amazing planets in our solar system. With viv...

Exam Board: AQALevel: GCSESubject: PhysicsFirst Teaching: September 2016First Exam: June 2018AQA approved.Apply and develop your students' knowledge and understanding of Physics with this textbook that builds mathematical skills, provides practical assessment guidance and supports all the required practicals.- Provides supp...

This book is written as a result of a personal conviction of the value of incorporating historical material into the teaching of chemistry, both at school and undergraduate level. Indeed, it is highly desirable that an undergraduate course in chemistry incorporates a separate module on the history of chemistry. This book is therefore aimed at teachers and students of chemistry, and it will also appeal to practising chemists. While the last 25 years has seen the appearance of a large number...

This collection of essays by scholars with expertise in a range of fields, cultural professionals and policy makers explores different ways in which the arts and humanities contribute to dealing with the challenges of contemporary society in ways that do not rely on simplistic and questionable notions of socio-economic impact as a proxy for value.

Early readers learn about different animal habitats.

THE MAGIC SCHOOL BUS PRESENTS INSECTS is a photographic nonfiction companion book to the original bestselling title, THE MAGIC SCHOOL BUS INSIDE A BEEHIVE.INSIDE A BEEHIVE from the bestselling Magic School Bus series taught thousands of kids about bees. MAGIC SCHOOL BUS PRESENTS INSECTS will expand upon the original title with fresh and updated content about all the incredible insects flying and crawling around the earth. With vivid full-color photographs on each page as well as il...

New series from DK designed to help kids learn how to read and learn to love readingRainforest Explorer is a 'Starting To Read Alone' reader, perfect for children beginning to read alone as they develop skills to read confidently, accurately, fluently and with good understanding. DK Reads proves that good reads build great readers.Through her blogs, Zoe shares the thrill and narrow escapes of her travels through the Amazon rainforest to her uncle's Researc...

The aim of this book is to identify the main areas of active discussion about, and research into, the biology of animal behaviour, to describe and assess ways in which these can be studied and using selected examples, to illus trate the kinds of results which are emerging. It is not intended to provide an exhaustive review of all we know about animal behaviour, although the examples have been chosen to cover as many as possible of the things that animals do. XlV Preface Acknowledgements I ...

Do you think science is fun and exciting? Bill Nye does. In fact, he wanted to become an astronaut, but NASA rejected his applications. Instead, Nye has spent his career helping other people understand science and showing them how cool science can be.Nye went to college to become a mechanical engineer, and he got a job working for an aircraft company. But soon, he began focusing more and more on a career in comedy. Eventually, he got his own popular TV show, called Bill Nye the...