Introduces plant reproduction, discussing how plants grow and develop and what influences the growth, and describes their role in ecosystems.

For many of us, plants herald the change of seasons, represent the promise of nourishment, or serve as stunning visual reminders of Earth’s natural beauty. As

Formalizing study of the natural world may seem like a daunting task considering the sheer breadth and variety of living things that inhabit the planet. From th

Introduces the microorganisms; discusses the physical characteristics, life cycle, and uses for bacteria; and describes the different types of algae.

Life comes in all shapes and forms, and living entities dwell in all types of habitats. There are seven characteristics that all life forms share—the ability t