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.
CK-12 Foundation
Ck 12: Life Science: Insect Reproduction and Life Cycle
[Free Registration/Login may be required to access all resource tools.] Most insects can reproduce quickly within a short period of time, which means they evolve faster and can adjust to environmental changes. Most reproduce by sexual...
Khan Academy
Khan Academy: The Biology of Zika Virus
Learn about the basic biology, origins, life cycle, and symptoms of Zika virus.
BiologyWise
Biology Wise: Life Cycle of an Amoeba
The amoeba is a unicellular protozoan organism that has existed since prehistoric times. Its physical characteristics, life cycle, and metabolic activities are described in this resource.
Massachusetts Institute of Technology
Mit: Open Course Ware: Courses: Biology: Cell Biology
College-level course highlighting the biology of cells of higher organisms. Course topics include cellular membranes and organelles; cell growth and oncogenic transformation; transport, receptors, and cell signaling; the cytoskeleton,...
CK-12 Foundation
Ck 12: Biology: Reproductive Life Cycles
[Free Registration/Login may be required to access all resource tools.] An overview of three types of sexual life cycles.
BiologyWise
Biology Wise: Carbon Cycle Diagram
Explains what the carbon cycle is and the basic steps in the cycle.
Sumanas
Sumanas Inc: Life: The Science of Biology: The Ovarian and Uterine Cycles
An opportunity for understanding the biology of the female reproductive system through animated presentations and test understanding with a quiz.
McGraw Hill
Glencoe Biology: Cell Cycle Regulation: Self Check Quiz
Try these five multiple-choice questions about cell cycle regulation. After submitting answers, students can review the material.
TeachEngineering
Teach Engineering: Carbon Cycles
Middle schoolers are introduced to the concept of energy cycles by learning about the carbon cycle. They will learn how carbon atoms travel through the geological (ancient) carbon cycle and the biological/physical carbon cycle. Students...
Morning Earth
How Life Works: Biosphere Is Process: Rock Cycle: The Marriage of Water and Rock
Students examine the biology topic of ecology. The tutorial includes definitions, questions, and pictures on rock cycles.
Sumanas
Sumanas Inc: Life: The Science of Biology: Life Cycle of a Moss
Studying mosses? Here is a great animation on the reproductive cycle of a moss.
US Geological Survey
Mercury in the Geochemical Cycle
Mercury in the geochemical cycle ultimately affects the food chain. Learn about this and its effect on the Everglades.