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Learn high school biology using videos, articles, and NGSS-aligned practice. Explore the fundamentals of cells, organism growth and development, photosynthesis and cellular respiration, molecular and classical genetics, natural selection and evolution, biodiversity and human impacts, and ecology.
Pygmy hippopotamus. Learn for free about math, art, computer programming, economics, physics, chemistry, biology, medicine, finance, history, and more. Khan Academy is a nonprofit with the mission of providing a free, world-class education for anyone, anywhere.
Learn for free about math, art, computer programming, economics, physics, chemistry, biology, medicine, finance, history, and more. Khan Academy is a nonprofit with the mission of providing a free, world-class education for anyone, anywhere.
MAP Recommended Practice 55 units · 1,645 skills. Unit 1 Geometry < 159. Unit 2 Geometry 159-175. Unit 3 Geometry 176-188. Unit 4 Geometry 189-200. Unit 5 Geometry 201-210. Unit 6 Geometry 211-217. Unit 7 Geometry 218-221. Unit 8 Geometry 222-226.
Biology at Khan Academy explores life in all its forms, from humans to bacteria and how living things convert energy, grow, and reproduce. The course covers key biological molecules, the role of DNA, and the complexity of cells.
The ability to maintain different environments inside a single cell allows eukaryotic cells to carry out complex metabolic reactions that prokaryotes cannot. In fact, it’s a big part of the reason why eukaryotic cells can grow to be many times larger than prokaryotic ones.
The diameter of DNA is always 2 nm; the distance between two curls in 3.4 nm and the distance between base pairs in 0.34 nanometers. The length varies depending on the organism.
