Students have the opportunity to take this five question pretest to assess their knowledge of the principles of regulation in the human body.

[Free Registration/Login may be required to access all resource tools.] Explains the four principles that unify biology - cell theory, gene theory, homeostasis, and evolution.

[Free Registration/Login may be required to access all resource tools.] Covers four unifying principles of biology: cell theory, gene theory, homeostasis, and evolutionary theory.

In this unit you will learn about the origin of the cells and their differences. It includes 15 interactive activities.

Discusses the five characteristics that living things have and nonliving things do not.

Find out about the characteristics and components of blood with informational text, diagrams, examples, and review questuons.

After studying this article, students will be able to identify the functions and structure of bones, types of bones, bone development, parts of bones, types of joints, and bone disorders.

[Free Registration/Login may be required to access all resource tools.] Videos, texts, activities, and assessments about the factors that characterize living things.

Describes the seven characteristics that define life - cells, homeostasis, heredity, use of energy, reproduction, response to environmental stimuli, and evolution and adaptation.

[Free Registration/Login may be required to access all resource tools.] The cells of protists need to perform all of the functions that other cells do, such as grow and reproduce, maintain homeostasis, and obtain energy. They also need...

This comprehensive study guide covers the main terms and concepts needed for a unit on the organization levels in the human body from organ systems to cells.