When DNA research first began, it required almost an entire day to extract the molecules from a cell nucleus. Now it requires less than an hour. Scholars learn about the early theories of DNA with an online interactive, videos,...

Could you go without your cell phone for 48 hours? Pose this question to your class and then read the article provided here. Pupils mark the text and and complete a graphic organizer that requires the use of textual evidence.

This study resource from Khan Academy provides practice questions for the MCAT. "Cell theory" questions are provided on this resource.

Learn how the Cell Theory defines living organisms.

Two multiple-choice quizzes about cells. The first is on cell theory, basic information about cells, and cell types. The second is on cell structures and functions.

[Free Registration/Login may be required to access all resource tools.] Read grade-level texts, complete activities, and take assessments about cell biology.

[Free Registration/Login may be required to access all resource tools.] A cell is the smallest structural and functional unit of an organism. Learn more about cell biology in this learning module produced by CK-12.

[Free Registration/Login may be required to access all resource tools.] Introduces cells, cell theory, and the levels of organization in organisms.

[Free Registration/Login may be required to access all resource tools.] Discusses how cells are organized in living things and explains the origin and significance of multicellular organisms.

This study resource from Khan Academy provides practice questions for the MCAT. "Cellular development" questions are provided on this resource.

[Free Registration/Login may be required to access all resource tools.] How Wegener's hypothesis of continental drift was refined.