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This video teaches about protein synthesis.

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An international team led by Professor Itai YanaAi of the Technion-Israel Institute of Technology Department of Biology made the discovery after using an extraordinarily powerful technique known as CEL-Seq. CEL-Seq monitors individual cells for their gene activity (as detected via mRNA)-and they applied it across 10 different species, with CEL-Seq being applied to 70 embryos per species. In particular, they were interested in whether the animal classification of phylum-which separates animals into groups according to their body plans-is actually a useful tool for placing animals into groups, as well as what genetic attributes are the same and different between the different phyla.

Why does a snake have 25 or more rows of ribs, whereas a mouse has only 13? The answer, according to a new study, may lie in "junk DNA," large chunks of an animal's genome that were once thought to be useless. The findings could help explain how dramatic changes in body shape have occurred over evolutionary history. Scientists began discovering junk DNA sequences in the 1960s. These stretches of the genome-also known as noncoding DNA-contain the same genetic alphabet found in genes, but they don't code for the proteins that make us who we are. As a result, many researchers long believed this mysterious genetic material was simply DNA debris accumulated over the course of evolution. But over the past couple decades, geneticists have discovered that this so-called junk is anything but. It has important functions, such as switching genes on and off and setting the timing for changes in gene activity. 

Topic: Turgor Pressure Why does a touch me not plant close? Hey!! Don't touch that plant. You will get scared. See, you did not listen to me. Don't worry!! Nothing to be scared about. Let me tell you more about this plant. This plant is called the Mimosa Pudica plant. Another name for it is "Touch Me Not" Plant. When anyone touches this plant, it closes its leaves with the help of pulvini. Pulvini are present at the base of each leaflet. They consist of cells filled with water. This water applies pressure against the walls of the cells. This pressure is called the turgor pressure. It helps the leaflets to stand upright. Now, when we touch a leaflet of the touch me not plant, specific parts of the plant release certain chemicals. These chemicals cause the cells in the pulvini to lose water. When water is lost, there is no more turgor pressure. As a result, the cells collapse, resulting in the closing of leaflets.

Series of review handouts from Living Systems Regents course

This directed case study examines the molecular basis of cystic fibrosis to emphasize the relationship between the genetic code stored in a DNA sequence and the encoded protein's structure and function. Cystic fibrosis is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) protein that functions to help maintain salt and water balance along the surface of the lung and gastrointestinal tract. This case introduces students to "Maggie," who has just been diagnosed with cystic fibrosis. The students must identify the mutation causing Maggie's disease by transcribing and translating a portion of the wildtype and mutated CFTR gene. Students then compare the three-dimensional structures of the resulting proteins to better understand the effect a single amino acid mutation can have on the overall shape of a protein. Students also review the concepts of tonicity and osmosis to examine how the defective CFTR protein leads to an increase in the viscosity of mucus in cystic fibrosis patients. This case was developed for use in an introductory college-level biology course but could also be adapted for use in an upper-level cell or molecular biology course.

This "clicker case" tells the story of "Hannah," a baby girl adopted by two loving parents who grows up with an uncontrolled appetite and develops severe early-onset obesity. Students follow Hannah's story as she develops excessive eating early in life, which her health care team is unable to explain. A visit to obesity specialists finally reveals the underlying cause of Hannah's obsession with food: extremely low levels of circulating leptin, a hormone that regulates appetite and body weight. It is further discovered that Hannah's leptin deficiency is due to a mutation in the LEP gene. As the story unfolds, students first work on unit conversions and BMI calculations to practice quantitative skills as well as graph and data interpretation skills. Students then apply their knowledge of DNA transcription, translation, and protein structure to answer questions based on figures from a 2019 study on LEP mutations. The case is best suited for high school and lower-level undergraduate biology courses.