Chapter 1 - Classifying Living Things
Unit A - Diversity of Life
- Chapter 1 - Classifying Living Things
how do scientists classify Earth's living things?

What's the Big Idea About Biodiversity?
It's the differences in this world that make all the difference! Find out why biodiversity is so important to our planet—and what you can do to help protect it.

What Do You Know About Biodiversity?
Invasive species, endangered species, the Endangered Species Act—when it comes to biodiversity, is your knowledge thriving or close to extinct? Find out with this interactive quiz.

Article
Who Are the Plants?
There are 10 divisions in the plant kingdom. The largest order, flowering plants, has 235,000 species. The smallest, gingkoes, has a single species. Learn more about the orders in the kingdom Plantae.

Diagram
Leaf Shape
More than likely with a good guess you could detect a heart-shaped leaf from one that's oval or narrow. But do you know how to recognize a leaf that has a lobed or divided shape? Learn how.

Young Naturalist Awards Essay
Saguaro Cactus: From Life to Death
2003 Young Naturalist Award-winning essay - Journey to the Sonoran Desert in southern Arizona with this seventh-grader for an up-close and personal look at the saguaro cactus, which can live about 200 years and grow to be almost 80 feet tall.

Online Resource, Activity
Science Explorations
A series of online investigations featuring scientific discoveries from Museum’s experts. Science Explorations is a collaboration between the Museum and Scholastic, the global children’s publishing, education, and media company, created to promote science literacy among students in grades 3 through 10.

Curriculum Materials
Arthropod Identification
What makes a beetle a beetle? How does a beetle behave? And what on Earth does a beetle have in common with a lobster? These activities can help your students develop an understanding of arthropods and learn techniques for observing arthropods in the field.

Article
Let's Talk with Ian Harrison about How Marine Animals Breathe
When in comes to breathing under water, marine organisms breathe in different ways. Some absorb oxygen through their skin, some rely on gills, and others gulp air into their gas bladders.

Slowing the Flow
All mammals—dogs, sea lions, and even you—have an adaptation for surviving in cold water. Take the plunge, and learn why the mammalian diving reflex is your cold-water friend.

Article
Bats: Twilight Zone (Science World)
Did you know that there are more than 1,100 different bat species? Or that scientists have not yet figured out how all these species are related? Explore the challenges of studying these night fliers.