This scoring guide can be used as a study guide, provding examples and exemplary student responses. The topic covered is energy flow in ecosystems.

Photomicrographs and diagrams make this resource a great tool for studying reproduction and development. Use this along with your lab material on plants.

[Free Registration/Login may be required to access all resource tools.] Defines and describes red blood cells and white blood cells, and describes the roles of platelets.

[Free Registration/Login may be required to access all resource tools.] Covers the role of the lymphatic system in the immune response.

[Free Registration/Login may be required to access all resource tools.] Introduces cells, tissues, organs, and organ systems in the human body.

[Free Registration/Login may be required to access all resource tools.] Covers female reproductive structures and their functions.

[Free Registration/Login may be required to access all resource tools.] Describes the two major divisions of the peripheral nervous system and their functions.

Proteoglycans are a type of protein that help in maintaining the integrity of connective tissue. Their chemical structure is quite complex and is explained here with the aid of labeled illustrations. Their functions in the support of...

This online biology book chapter offers definitions and descriptions of the nervous system's components.

Whether your child is lost in a haze of elementary grammar rules, sinking fast in a jumble of Newton's laws in middle school, or lost in the details of an AP biology class, you need help quickly, before your child falls way behind the...

Describes the main tissue types and organ systems of the body and how they function together.

Learn about the three types of muscle tissue, how a muscle contracts, and how muscles are adapted for exercise. [3:40]