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Why Are All Humans Unique? Meiosis: Crash Course Biology #30
Why Are All Humans Unique? Meiosis: Crash Course Biology #30 Teacherflix 2 Views • 1 year ago

Ever wonder why we aren’t exact clones of our parents, or why siblings aren’t exactly alike? The reason traces back to meiosis. In this episode of Crash Course Biology, we’ll discover how egg and sperm cells get made and learn why you’re a totally unique remix of your parents’ DNA.

Introduction: Why Are We All Unique? 0:00
Gametes 1:33
Meiosis 4:09
The Phases of Meiosis 4:44
Nondisjunction 7:14
Why We Aren't Clones 8:18
Meiosis & Genetic Diversity 9:49
Review & Credits 11:32

This series was produced in collaboration with HHMI BioInteractive, committed to empowering educators and inspiring students with engaging, accessible, and quality classroom resources. Visit
https://BioInteractive.org/CrashCourse for more information.

Check out our Biology playlist here: https://www.youtube.com/playli....st?list=PL8dPuuaLjXt

Watch this series in Spanish on our Crash Course en Español channel here: https://www.youtube.com/playli....st?list=PLkcbA0DkuFj

Sources: https://docs.google.com/docume....nt/d/1GLDtAXE6ekg4Ch

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David Fanska, Andrew Woods, Sean Saunders, DL Singfield, Ken Davidian, Stephen Akuffo, Toni Miles, Steve Segreto, Kyle & Katherine Callahan, Laurel Stevens, Burt Humburg, Aziz Y, Perry Joyce, Scott Harrison, Mark & Susan Billian, Alan Bridgeman, Breanna Bosso, Matt Curls, Jennifer Killen, Starstuff42, Jon Allen, Sarah & Nathan Catchings, team dorsey, Bernardo Garza, Trevin Beattie, Eric Koslow, Indija-ka Siriwardena, Jason Rostoker, Siobhán, Ken Penttinen, Nathan Taylor, Barrett & Laura Nuzum, Les Aker, William McGraw, Vaso, ClareG, Rizwan Kassim, Constance Urist, Alex Hackman, pinapples of solidarity, Katie Dean, Stephen McCandless, Thomas Greinert, Wai Jack Sin, Ian Dundore, Caleb Weeks
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How to Make Tough Decisions: Crash Course Business - Soft Skills #11
How to Make Tough Decisions: Crash Course Business - Soft Skills #11 Teacherflix 2 Views • 1 year ago

We make small choices like what to eat for lunch, but we also have to set goals, pick a career, and decide how to invest our hard-earned money. It’s not easy! We don’t want to make a decision out of fear, rather than doing what’s best for us. And we don’t want to regret a big choice and dwell on the “what ifs” either.

So today, we’re going to take a step back, understand how to really look at the decisions we’re making, and learn what not to do when facing a difficult choice.

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Crash Course is on Patreon! You can support us directly by signing up at
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Eric Prestemon, Sam Buck, Mark Brouwer, Jonathan Zbikowski, Siobhan Sabino, Zach Van Stanley, Bob Doye, Jennifer Killen, Naman Goel, Nathan Catchings, Brandon Westmoreland, dorsey, Indika Siriwardena, Kenneth F Penttinen, Trevin Beattie, Erika & Alexa Saur, Glenn Elliott, Justin Zingsheim, Jessica Wode, Tom Trval, Jason Saslow, Nathan Taylor, Brian Thomas Gossett, Khaled El Shalakany, SR Foxley, Sam Ferguson, Yasenia Cruz, Eric Koslow, Caleb Weeks, Tim Curwick, D.A. Noe, Shawn Arnold, Malcolm Callis, William McGraw, Andrei Krishkevich, Rachel Bright, Jirat, Ian Dundore
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Understanding Financial Statements and Accounting: Crash Course Entrepreneurship #15
Understanding Financial Statements and Accounting: Crash Course Entrepreneurship #15 Teacherflix 2 Views • 1 year ago

Honestly, “spreadsheets” are kind of the vegetables of the business world -- the very idea of them makes some people queasy. But that’s ok! They can be intimidating, but they’re not impossible to understand. Today we’re going to learn to love ‘em, because basic accounting can make or break a business. If we lose track of expenses or overestimate a revenue stream, we might end up questioning where all the money has gone.

Software Advice:
https://blog.hubspot.com/sales..../small-business-acco

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Crash Course is on Patreon! You can support us directly by signing up at http://www.patreon.com/crashcourse

Thanks to the following patrons for their generous monthly contributions that help keep Crash Course free for everyone forever:

Eric Prestemon, Sam Buck, Mark Brouwer, Indika Siriwardena, Avi Yashchin, Timothy J Kwist, Brian Thomas Gossett, Haixiang N/A Liu, Jonathan Zbikowski, Siobhan Sabino, Zach Van Stanley, Jennifer Killen, Nathan Catchings, Brandon Westmoreland, dorsey, Kenneth F Penttinen, Trevin Beattie, Erika & Alexa Saur, Justin Zingsheim, Jessica Wode, Tom Trval, Jason Saslow, Nathan Taylor, Khaled El Shalakany, SR Foxley, Sam Ferguson, Yasenia Cruz, Eric Koslow, Tim Curwick, David Noe, Shawn Arnold, William McGraw, Andrei Krishkevich, Rachel Bright, Jirat, Ian Dundore
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Distances: Crash Course Astronomy #25
Distances: Crash Course Astronomy #25 Teacherflix 2 Views • 1 year ago

How do astronomers make sense of the vastness of space? How do they study things so far away? Today Phil talks about distances, going back to early astronomy. Ancient Greeks were able to find the size of the Earth and from that the distance to and the sizes of the Moon and Sun. Once the Earth/Sun distance was found, parallax was used to find the distance to nearby stars, and that was bootstrapped using brightness to determine the distances to much farther stars.

Check out the Crash Course Astronomy solar system poster here:
http://store.dftba.com/product....s/crashcourse-astron

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Chapters:
Introduction 00:00
How did we calculate the Earth's Size? 1:07
THE Astronomical Unit (AU) = 149,597,870.7 km 3:12
Depth Perception & Parallax 5:39
Light Years & Parsecs 7:31
Brightness Indicates Distance 9:07
Review 10:30
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PBS Digital Studios: http://youtube.com/pbsdigitalstudios

Follow Phil on Twitter: https://twitter.com/badastronomer

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PHOTOS/VIDEOS
Lunar Ecplise http://www.slate.com/content/d....am/slate/blogs/bad_a [credit: Phil Plait]
Venus & Mercury [credit: Phil Plait]
Venus Transit https://www.youtube.com/watch?v=34mXua1n_FQ [credit: NASA]
Black Drop Venus Transit https://en.wikipedia.org/wiki/....Black_drop_effect#me [credit: Wikimedia Commons, H. Raab, Johannes-Kepler-Observatory]
New Horizons Approaching Pluto and Charon https://en.wikipedia.org/wiki/....New_Horizons#/media/ [credit: NASA/JHU APL/SwRI/Steve Gribben]
Radio Telescopes Diagram http://scitechdaily.com/images..../Radio-Telescopes-Se [credit: Alexandra Angelich, NRAO/AUI/NSF]
61 Cygni https://archive.stsci.edu/cgi-bin/dss_search?v=poss1_red&r=21+06+54.60&d=%2B38+44+44.9&e=J2000&h=30&w=30&f=gif&c=none&fov=NONE&v3= [credit: Caltech / National Geographic Society / STScI]
Proxima Centauri https://www.spacetelescope.org/images/potw1343a/ [credit: ESA/Hubble & NASA]
Dying Star http://www.nasa.gov/images/con....tent/64884main_image [credit: NASA, ESA, HEIC, and The Hubble Heritage Team (STScI/AURA)]
Exploding Star http://www.nasa.gov/multimedia..../imagegallery/image_ [credit: NASA, ESA, J. Hester, A. Loll (ASU)]
Animation of a Variable Star http://www.spacetelescope.org/videos/heic1323j/ [credit: NASA, ESA, M. Kornmesser]
Hubble's High-Definition Panoramic View of the Andromeda Galaxy http://hubblesite.org/newscent....er/archive/releases/ [credit: NASA, ESA, J. Dalcanton, B.F. Williams, and L.C. Johnson (University of Washington), the PHAT team, and R. Gendler]

Polarity, Resonance, and Electron Pushing: Crash Course Organic Chemistry #10
Polarity, Resonance, and Electron Pushing: Crash Course Organic Chemistry #10 Teacherflix 2 Views • 1 year ago

We’ve all heard the phrase “opposites attract.” It may or may not be true for people, but it’s definitely true in organic chemistry. In this episode of Crash Course Organic Chemistry, we’re learning about electronegativity, polarity, resonance structures, and resonance hybrids. We’ll practice a very important skill for this course that will help us avoid a lot of memorization in the future: electron pushing. It’ll be a lot of trial and error at first, but we all start somewhere!

Episode Sources:
“THINK BIG! Must the molecules of life always be Left-Handed or Right-Handed?” Smithsonian Magazine.
Spinoff 2004 - “A NATURAL WAY TO STAY SWEET”, NASA.

Series Sources:
Brown, W. H., Iverson, B. L., Ansyln, E. V., Foote, C., Organic Chemistry; 8th ed.; Cengage Learning, Boston, 2018.
Bruice, P. Y., Organic Chemistry, 7th ed.; Pearson Education, Inc., United States, 2014.
Clayden, J., Greeves, N., Warren., S., Organic Chemistry, 2nd ed.; Oxford University Press, New York, 2012.
Jones Jr., M.; Fleming, S. A., Organic Chemistry, 5th ed.; W. W. Norton & Company, New York, 2014.
Klein., D., Organic Chemistry; 1st ed.; John Wiley & Sons, United States, 2012.
Louden M., Organic Chemistry; 5th ed.; Roberts and Company Publishers, Colorado, 2009.
McMurry, J., Organic Chemistry, 9th ed.; Cengage Learning, Boston, 2016.
Smith, J. G., Organic chemistry; 6th ed.; McGraw-Hill Education, New York, 2020.
Wade., L. G., Organic Chemistry; 8th ed.; Pearson Education, Inc., United States, 2013.

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Phil Simmons, Alexander Thomson, Mark & Susan Billian, Eric Z, Alan Bridgeman, Jennifer Smith, Matt Curls, Tim Kwist, Ron Lin, Jonathan Zbikowski, Jennifer Killen, Sarah & Nathan Catchings, Brandon Westmoreland, dorsey, Trevin Beattie, Eric Prestemon, Yasenia Cruz, Eric Koslow, Indika Siriwardena, Khaled El, Shalakany, Shawn Arnold, Tom Trval, Siobhán, Ken Penttinen, Nathan Taylor, William McGraw, Justin Zingsheim, Andrei Krishkevich, Jirat, Brian Thomas Gossett, SR Foxley, Ian Dundore, Jason A Saslow, Jessica Wode, Mark, Caleb Weeks, Sam Buck, Catherine Conroy, Patty Laqua, Leonora Rossé Muñoz, Stephen Saar, John Lee
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World War II Part 1: Crash Course US History #35
World War II Part 1: Crash Course US History #35 Teacherflix 2 Views • 1 year ago

In which John Green teaches you about World War II, a subject so big, it takes up two episodes. This week, John will teach you how the United States got into the war, and just how involved America was before Congress actually declared war. John will actually talk a little about the military tactics involved, and he'll get into some of the weaponry involved, specifically the huge amount of aerial bombing that characterized the war, and the atomic bombs that ended the war in the Pacific.

Hey teachers and students - Check out CommonLit's free collection of reading passages and curriculum resources to learn more about the events of this episode. Americans entered World War II after the attack on Pearl Harbor:
https://www.commonlit.org/text....s/the-attack-on-pear
A call for soldiers led to an early civil rights victory, the Tuskegee Airmen: https://www.commonlit.org/texts/tuskegee-airmen
America led the invasion of Normandy that would end the war, and American troops helped to liberate surviving Jews from Nazi concentration camps throughout Europe: https://www.commonlit.org/text....s/liberation-of-nazi

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Learn more about WWII in these other Crash Course videos:
Crash Course World History:
World War II (38): https://www.youtube.com/watch?v=Q78COTwT7nE
World War II, A War for Resources (220): https://www.youtube.com/watch?v=H-2q-QMUIgY

Crash Course European History:
World War II (38): https://www.youtube.com/watch?v=Hs_JMydrxZM
World War II Civilians and Soldiers (39): https://www.youtube.com/watch?v=rlx6ur_D51s
The Holocaust, Genocides, and Mass Murder of WWII (40): https://www.youtube.com/watch?v=iQeDvnapdlg
Post-World War II Recovery (42): https://www.youtube.com/watch?v=nlp068CmQaE

Crash Course Black American History:
World War II (31): https://www.youtube.com/watch?v=U7wrwPnQVg4
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Chapters:
Introduction: WWII 00:00
American Isolationism Pre-WWII 1:07
American Support for Allies in WWII 3:38
Pearl Harbor 5:03
WWII Fighting in the Pacific 5:43
WWII Fighting in Europe 6:35
Mystery Document 7:30
The End of WWII 8:38
Hiroshima, Nagasaki, & the Atomic Bomb 9:25
Credits 12:54


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Japan in the Heian Period and Cultural History: Crash Course World History 227
Japan in the Heian Period and Cultural History: Crash Course World History 227 Teacherflix 2 Views • 1 year ago

In which John Green teaches you about what westerners call the middle ages and the lives of the aristocracy...in Japan. The Heian period in Japan lasted from 794CE to 1185CE, and it was an interesting time in Japan. Rather than being known for a thriving economy, or particularly interesting politics, the most important things to come out of the Heian period were largely cultural. There was a flourishing of art and literature in the period, and a lot of that culture was created by women. The Tale of Genji by Murasaki Shikibu was the classic piece of literature of the day, and it gave a detailed look into the way the Aristocrats of the Heian period lived. While this doesn't give a lot of insight into the lives of daily people, it can be very valuable, and the idea of approaching history from a cultural perspective is a refreshing change from the usual military or political history that survives from so many eras.

Citation 1: Morris, Ivan, The World of the Shining Prince: Court Life in Ancient Japan. Vintage Books. 2013. p. 5
Citation 2: Morris, p. 14
Citation 3: Morris, p. 67
Citation 4: Morris, p. 114
Citation 5: Morris, p. 147
Citation 6: Quoted in Morris, p. 112
Citation 7: Morris, p. 198

Crash Course is on Patreon! You can support us directly by signing up at
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Gamma-Ray Bursts: Crash Course Astronomy #40
Gamma-Ray Bursts: Crash Course Astronomy #40 Teacherflix 2 Views • 1 year ago

Gamma-ray bursts are not only incredible to study, but their discovery has an epic story all its own. Today Phil takes you through some Cold War history and then dives into what we know. Bursts come in two rough varieties: Long and short. Long ones are from hypernovae, massive stars exploding, sending out twin beams of matter and energy. Short ones are from merging neutron stars. Both kinds are so energetic they are visible for billions of light years, and both are also the birth announcements of black holes.

Check out the Crash Course Astronomy solar system poster here:
http://store.dftba.com/product....s/crashcourse-astron

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Chapters:
Introduction 00:00
Gamma Ray Bursts and the Cold War 00:45
Where Do Gamma Ray Bursts Come From? 3:26
What Causes Gamma Ray Bursts? 6:11
Kinds of Gamma Ray Bursts: Long and Short 8:35
What Would Happen if a Gamma Ray Burst Hit Earth? 10:24
Review 12:53
--

PBS Digital Studios: http://youtube.com/pbsdigitalstudios

Follow Phil on Twitter: https://twitter.com/badastronomer

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PHOTOS/VIDEOS
Nuclear Bomb Images via Wikimedia Commons:
Operation Upshot Knothole https://en.wikipedia.org/wiki/....File:Operation_Upsho
Ivy Mike https://en.wikipedia.org/wiki/File:IvyMike2.jpg
Castle Bravo https://en.wikipedia.org/wiki/....Castle_Bravo#/media/
Upshot Knothole GRABLE https://en.wikipedia.org/wiki/....File:Upshot-Knothole
President Kennedy signs the Limited Nuclear Test Ban Treaty https://en.wikipedia.org/wiki/....Partial_Nuclear_Test [credit: Wikimedia Commons]
Vela http://www.losangeles.af.mil/s....hared/media/photodb/ [credit: USAF]
The Crab Nebula https://www.nasa.gov/multimedi....a/imagegallery/image [credit: NASA, ESA, J. Hester, A. Loll (ASU)]
Solar Flare http://www.nasa.gov/mission_pa....ges/sunearth/news/Ne [credit: NASA/SDO/AIA]
Gamma Ray Burst http://svs.gsfc.nasa.gov/cgi-b....in/details.cgi?aid=2 [credit: NASA/Goddard Space Flight Center Conceptual Image Lab]
Four ALMA antennas on the Chajnantor plain http://www.eso.org/public/images/alma-jfs-2010-10/ [credit: ESO/José Francisco Salgado (josefrancisco.org)]
Gamma Ray Burst 970228 https://www.spacetelescope.org/images/opo9730b/ [credit: Andrew Fruchter (STScI), Elena Pian (ITSRE-CNR), and NASA/ESA]
HST/STIS Image of the optical afterglow of w:GRB 970508 https://en.wikipedia.org/wiki/....GRB_970508#/media/Fi [credit: STScI/NASA]
Black Holes: Monsters in Space http://www.nasa.gov/mission_pa....ges/nustar/multimedi [credit: NASA/JPL-Caltech]
Naked-Eye Gamma-ray Burst Model for GRB 080319B http://svs.gsfc.nasa.gov/cgi-b....in/details.cgi?aid=1 [credit: NASA/Swift/Cruz deWilde]
2008 GRB http://www.nasa.gov/images/con....tent/218810main_grb_ [credit: NASA/Swift/Stefan Immler, et al.]
GRB Data http://www.nasa.gov/images/con....tent/134782main_GRB_ [credit: NASA]
Imagine two massive stars born together as a binary star http://chandra.harvard.edu/pho....to/2005/j0806/wd_lg. [credit: NASA/GSFC/D. Berry]
Colliding Binary Neutron stars http://chandra.harvard.edu/res....ources/animations/ne [credit: NASA/D.Berry]
Black Hole Devours a Neutron Star http://chandra.harvard.edu/res....ources/animations/ne [credit: NASA/D.Berry]
Eta Carinae https://en.wikipedia.org/wiki/....Eta_Carinae#/media/F [credit: Jon Morse (University of Colorado) & NASA Hubble Space Telescope]
WR 104: A Pinwheel Star System http://apod.nasa.gov/apod/ap140603.html [credit: P. Tuthill (U. Sydney) & J. Monnier (U. Michigan), Keck Obs., ARC, NSF]
Swift HD Beauty Shot http://svs.gsfc.nasa.gov/cgi-b....in/details.cgi?aid=1 [credit: NASA/Goddard Space Flight Center]
Swift's 500 Gamma-ray Bursts http://svs.gsfc.nasa.gov/cgi-b....in/details.cgi?aid=1 [credit: NASA/Goddard Space Flight Center]

The Great Depression: Crash Course US History #33
The Great Depression: Crash Course US History #33 Teacherflix 2 Views • 1 year ago

In which John Green teaches you about the Great Depression. So, everybody knows that the Great Depression started with the stock market crash in 1929, right? Not exactly. The Depression happened after the stock market crash, but wasn't caused by the crash. John will teach you about how the depression started, what Herbert Hoover tried to do to fix it, and why those efforts failed.

Hey teachers and students - Check out CommonLit's free collection of reading passages and curriculum resources to learn more about the events of this episode. The Roaring Twenties ended with The Great Depression, a period of soul-searching for the United States dealing with a failing middle class:
https://www.commonlit.org/text....s/the-great-depressi
The issues of the Great Depression were made more difficult by the agricultural crisis known as the Dust Bowl: https://www.commonlit.org/text....s/excerpt-from-on-dr

Learn more about the Great Depression in episode #28 of Crash Course Black American History here: https://www.youtube.com/watch?v=f14kiGoexVg

Chapters:
Introduction: The Great Depression 00:00
Causes of the Great Depression 0:48
The Stock Market Crash 2:31
The Failures of America's Banking System 3:35
The Hoover Administration's Responses to the Great Depression 5:10
WWI's Global Economic Impact 5:40
Hoover and The Gold Standard 6:57
What Hoover did (and didn't) do about the Great Depression 8:13
The Reconstruction Finance Corporation 10:04
Impact of the Great Depression 10:30
Mystery Document 11:27
Accounts of the Great Depression 12:35
Credits 13:55

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