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Ck 12: Life Science: Gene Therapy
[Free Registration/Login may be required to access all resource tools.] Gene therapy is the insertion of genes into a person's cells to cure a genetic disorder. Could gene therapy be the cure for AIDS? No, AIDS is caused by a virus. Gene...
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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....
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Ck 12: Life Science: Rna
[Free Registration/Login may be required to access all resource tools.] DNA contains the instructions to create proteins, but it does not make proteins itself. DNA is located in the nucleus, which it never leaves, while proteins are made...
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Ck 12: Life Science: Puberty and Adolescence
[Free Registration/Login may be required to access all resource tools.] Puberty is the stage of life when a child becomes sexually mature. Puberty lasts from about 12 to 18 years of age in boys and from about 10 to 16 years of age in...
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Ck 12: Life Science: Human Egg Cells
[Free Registration/Login may be required to access all resource tools.] When a baby girl is born, her ovaries contain all of the eggs they will ever produce. But these eggs are not fully developed. They develop only after she starts...
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Ck 12: Biology: History of Life
[Free Registration/Login may be required to access all resource tools.] This comprehensive lesson by CK-12 explains how scientists learn about the past by examining and dating fossils.
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Ck 12: Life Science: Cellular Respiration
[Free Registration/Login may be required to access all resource tools.] How does the food you eat provide energy? Through the process of cellular respiration, the energy in food is changed into energy that can be used by the body's...
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Ck 12: Life Science: Fungi Classification
[Free Registration/Login may be required to access all resource tools.] Scientists used to think that fungi were members of the plant kingdom. They thought this because fungi had several similarities to plants. However, there are a...
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Ck 12: Life Science: Importance of Arthropods
[Free Registration/Login may be required to access all resource tools.] Arthropods might seem a little scary, but they are actually performing important roles in the environment. Arthropods are important to the ecosystem and to humans in...
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Ck 12: Life Science: Indoor Air Pollution
[Free Registration/Login may be required to access all resource tools.] Recall that air pollution is due to chemical substances and particles released into the air mainly by human actions. When most people think of air pollution, they...
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Ck 12: Life Science: Influences on Darwin
[Free Registration/Login may be required to access all resource tools.] When Darwin returned to England at the end of his voyage, he did not rush to announce his discoveries. He did not want to present any ideas unless he had strong...
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Ck 12: Life Science: Types of Echinoderms
[Free Registration/Login may be required to access all resource tools.] Birds aren't the only creatures that have feathers. One type of echinoderm, the feather star, has feathery arms. These animals don't fly or even move much at all....
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Ck 12: Life Science: Vertebrate Characteristics
[Free Registration/Login may be required to access all resource tools.] Vertebrates are animals with backbones. These include fish, amphibians, reptiles, birds, and mammals. Learn more about vertebrate characteristics in this learning...
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Ck 12: Life Science: Cardiovascular System Health
[Free Registration/Login may be required to access all resource tools.] There are many risk factors that can cause a person to develop cardiovascular disease. A risk factor is anything that is linked to an increased chance of developing...
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Ck 12: Life Science: Cardiovascular System
[Free Registration/Login may be required to access all resource tools.] Your cardiovascular system has many jobs. At times the cardiovascular system can work like a pump, a heating system, or even a postal carrier. To do these tasks,...
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Ck 12: Life Science: Importance of Insects
[Free Registration/Login may be required to access all resource tools.] Many insects are considered to be pests by humans. However, insects are also very important for numerous reasons. Learn more about the importance of insects in this...
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Ck 12: Life Science: Importance of Mammals
[Free Registration/Login may be required to access all resource tools.] Mammals play many important roles in ecosystems, and they also benefit people. Learn more about the importance of mammals in this learning module produced by CK-12.
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Ck 12: Life Science: Infancy and Childhood
[Free Registration/Login may be required to access all resource tools.] The first year after birth is called infancy. Infancy is a period when the baby grows very fast. During infancy, the baby doubles in length and triples in weight....
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Ck 12: Life Science: Inflammatory Response
[Free Registration/Login may be required to access all resource tools.] A scrape is a break in the skin that may let pathogens enter the body. If bacteria enter through the scrape, they could cause an infection. These bacteria would then...
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Ck 12: Life Science: Keeping the Nervous System Healthy
[Free Registration/Login may be required to access all resource tools.] Activities that challenge your brain, such as working on a Sudoku puzzle, are good for the health of your nervous system. Just like you need to work out your body to...
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Ck 12: Life Science: Central Nervous System
[Free Registration/Login may be required to access all resource tools.] The central nervous system (CNS) is the largest part of the nervous system. It includes the brain and the spinal cord. The bony skull protects the brain. The spinal...
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Ck 12: Life Science: Chemistry of Life
[Free Registration/Login may be required to access all resource tools.] Many chemical reactions are going on constantly inside your body. In fact, there are probably thousands of chemical reactions occurring every second in every one of...
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Ck 12: Life Science: Importance of Mollusks
[Free Registration/Login may be required to access all resource tools.] Mollusks are important in a variety of ways; they are used as food, for decoration, in jewelry, and in scientific studies. They are even used as roadbed material and...
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Ck 12: Life Science: Invertebrates
[Free Registration/Login may be required to access all resource tools.] Animals are also often identified as being either invertebrates or vertebrates. These are terms based on the skeletons of the animals. Vertebrates have a backbone...