Genetically modified foods have been around for decades. Created by altering the DNA of one organism through the introduction of genes from another, they are mainly found in processed foods that use corn, soybeans, sugar, beets, and in feed given to farm animals that people later consume. Supporters argue that genetic modification can make food more flavorful, nutritious, and abundant and enables plants to fight disease, resist pests, and survive drought. Opponents, however, question the safety of genetically modified foods, contend that their health benefits remain unproven, and fear their long-term impact on the environment, the food industry, and the human body. Is the world better off with or without genetically modified food?
How science should determine which unorthodox ideas to take seriously is a philosophical challenge, but in practice easy for scientists. Michael Gordon has ideas for improving the process. We should relax about harmless pseudoscience.
That a tiny collection of cells can divide, multiply, and transform into the proper combination of lung cells, brain cells, bone, muscle, and more—eventually becoming a fully formed human being—is often referred to as the miracle of life. But at the cellular level, this is the story of stem cells, cellular differentiation, and gene expression. This program explores these topics, detailing the different types of stem cells (embryonic and adult), and when they leave the cell cycle to enter differentiation. Cell mutation, gene expression, and the process of epigenetics are also covered. Stem cell potency is also reviewed, as is the role and promise of stem cells in medical research, including the pros and cons of using embryonic versus adult-derived stem cells.
Energy is never created nor destroyed; it is just transferred from one form to another. This video uses an engaging presenter and familiar objects and scenarios to explore different forms of energy, their effects on objects and processes, and conversion from one form to another. Sections include what is energy, kinetic energy (including electrical, radiant and sound), potential energy and energy transformations. Students of science at lower to middle levels will find this resource ideal for consolidating their understanding of these important fundamental areas.
All living organisms need energy to perform day-to-day tasks. Using straightforward, vibrant animation to anchor otherwise complex ideas, this program shows how that energy is created through the metabolic processes of catabolism, aerobic cellular respiration, and anabolism. Respiration is covered in depth, with detailed explanations of glycolysis, the Krebs cycle and the electron transport chain. Also covered is fermentation and anaerobic cellular respiration, and how cells help build large, complex molecules through the process of anabolism.
In recent years, climate science has come under attack, so concerned geologist Simon Lamb grabbed his camera and set out to explore the inside story of climate research. For over three years he followed scientists from a wide range of disciplines at work in the Arctic, Antarctic, Southern Ocean, New Zealand, Europe, and the United States. They talk about their work, hopes and fears with candor and directness, resulting in an intimate portrait of the global community of researchers racing to understand our planet's changing climate and provide a compelling case for rising CO2 as the main cause.
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