CK-12 Foundation
Ck 12: Biology: Carbon Cycle
Learn about the carbon cycle.[Free Registration/Login may be required to access all resource tools.]
CK-12 Foundation
Ck 12: Biology: Recycling Matter Study Guide
Review some of the cycles that recycle matter through Earth's biospheres.
CK-12 Foundation
Ck 12: Biology: Plant Life Cycles Study Guide
Understand the reproduction and life cycle of plants.
Biology Pages
Kimball's Biology Pages: The Carbon Cycle
Useful introduction to the carbon cycle with a diagram and a discussion of the effects of carbon dioxide on the greenhouse effect and global warming.
CK-12 Foundation
Ck 12: Biology: Cell Division and Cell Cycle Study Guide
This comprehensive study guide covers the main terms and concepts needed for a unit on cell division and the cell life cycle.
CK-12 Foundation
Ck 12: Biology: Krebs Cycle
[Free Registration/Login may be required to access all resource tools.] Describes the Krebs cycle.
CK-12 Foundation
Ck 12: Biology: Cell Cycle
[Free Registration/Login may be required to access all resource tools.] An overview of the eukaryotic cell cycle.
CK-12 Foundation
Ck 12: Biology: Cell Cycle
[Free Registration/Login may be required to access all resource tools.] An overview of the eukaryotic cell cycle.
Khan Academy
Khan Academy: Sexual Life Cycles
Tutorial takes a look at the three types of sexual life cycles used by different organisms: diploid-dominant, haploid-dominant, and alternation of generations.
Khan Academy
Khan Academy: Virus Structure and Reproductive Cycle Questions
These practice questions pertain to virus structure and reproductive cycle. This study resource from Khan Academy provides practice questions for the MCAT.
CK-12 Foundation
Ck 12: Biology: Life Cycle of Seedless Vascular Plants
[Free Registration/Login may be required to access all resource tools.] Describes the life cycle of seedless vascular plants.
CK-12 Foundation
Ck 12: Biology: Angiosperm Life Cycle
[Free Registration/Login may be required to access all resource tools.] Discusses the life cycle of angiosperms.
CK-12 Foundation
Ck 12: Biology: Menstrual Cycle
[Free Registration/Login may be required to access all resource tools.] Discusses the phases of the menstrual cycle.
CK-12 Foundation
Ck 12: Biology: Nitrogen Cycle
[Free Registration/Login may be required to access all resource tools.] Covers the nitrogen cycle.
CK-12 Foundation
Ck 12: Life Science: Cell Cycle
[Free Registration/Login may be required to access all resource tools.] The process of cell division in eukaryotic cells is carefully controlled. The cell cycle is the life cycle of a cell, with cell division at the end of the cycle....
CK-12 Foundation
Ck 12: Life Science: Water Cycle
[Free Registration/Login may be required to access all resource tools.] Water and elements like carbon and nitrogen are constantly being recycled through the environment. This process is called a biogeochemical cycle because it involves...
CK-12 Foundation
Ck 12: Life Science: Carbon Cycle
[Free Registration/Login may be required to access all resource tools.] Carbon is one of the most common elements found in living organisms. Chains of carbon molecules form the backbones of many molecules, such as carbohydrates,...
Morning Earth
Life Lives in Circles: Introduction Life Materials Cycle and Re Cycle
Scholars explore the Biology concept of life cycles. The tutorial consists of definitions, examples, and pictures. Topics include the great circle dance and life-materials.
CK-12 Foundation
Ck 12: Life Science: Menstrual Cycle
[Free Registration/Login may be required to access all resource tools.] The menstrual cycle is a series of changes in the reproductive system of mature females that repeats every month. Learn more about the menstrual cycle in this...
BiologyWise
Biology Wise: Lytic vs. Lysogenic Cycle
Explains in detail what the lytic and lysogenic cycles of a virus are and the stages of each cycle. Also presents a table highlighting the differences between them.
CK-12 Foundation
Ck 12: Life Science: Plant Reproduction and Life Cycle
[Free Registration/Login may be required to access all resource tools.] The life cycle of a plant is very different from the life cycle of an animal. Humans are made entirely of diploid cells (cells with two sets of chromosomes). Our...
CK-12 Foundation
Ck 12: Life Science: Nitrogen Cycle
[Free Registration/Login may be required to access all resource tools.] Like water and carbon, nitrogen is also repeatedly recycled through the biosphere. This process is called the nitrogen cycle. Learn more about the nitrogen cycle in...
BiologyWise
Biology Wise: Nitrogen Cycle Steps
Nitrogen is essential to all living things. This article explains what the nitrogen cycle is and the five steps involved in it.
Khan Academy
Khan Academy: Biogeochemical Cycles Review
Review information on the cycling of matter throughout the spheres of Earth.