Natural Selection – Crash Course Biology #14

Hank guides us through the process of natural selection, the key mechanism of evolution.

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Table of Contents:
1) Natural Selection 1:27
2) Adaptation 2:56
3) Fitness 3:36
4) Four Principals 3:54
a. Variations 4:01
b. Heritability 4:17
c. “The Struggle for Existence” 4:25
d. Survival and Reproductive Rates 5:00
5) Biolography 5:59
6) Modes of Selection 7:40
a. Directional Selection 8:17
b. Stabilizing Selection 8:56
c. Disruptive Selection 9:27
7) Sexual Selection 10:22
8) Artificial Selection 11:24

References for this episode can be found in the Google document here: http://dft.ba/-2Ank

This video uses the following sounds from Freesound.org:
“20071104.forest.04.binaural.mp3” by dobroide
“ForestBirds.wav” by HerbertBoland

crashcourse, science, biology, natural selection, genetics, peppered moth, inherited traits, population genetics, charles darwin, darwin, on the origin of species, evolution, adaptation, galapagos finches, fitness, variation, phenotype, heritable, malthus, survival rate, reproductive rate, crossbreeding, inbreeding, genotype, directional selection, stabilizing selection, disruptive selection, selective pressures, sexual selection, artificial selection, selective breeding

The Dark Ages…How Dark Were They, Really?: Crash Course World History #14

John Green teaches you about the so-called Dark Ages, which it turns out weren’t as uniformly dark as you may have been led to believe. While Europe was indeed having some issues, many other parts of the world were thriving and relatively enlightened. John covers European Feudalism, the cultural blossoming of the Islamic world, and the scientific and artistic advances in China, all during these “Dark Ages.” Along the way, John will raise questions about the validity of Europe’s status as a continent, reveal the best and worst years of his life, and frankly state that science and religion were once able to coexist.

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Meiosis: Where the Sex Starts – Crash Course Biology #13

Hank gets down to the nitty gritty about meiosis, the special type of cell division that is necessary for sexual reproduction in eukaryotic organisms.

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References for this episode can be found in the Google document here: http://dft.ba/-2wDm

Table of Contents
1) Homologous Chromosome Pairs 2:10
2) Primary Oocytes 3:30
3) Primary Spermatocytes 3:30
4) Meiosis 2:59
5) Interphase I 4:04
6) Prophase I 4:37
a) Crossover 5:05
b) Recombination 5:05
7) Metaphase I 7:53
8) Anaphase I 8:05
9) Telophase I 8:19
10) Prophase II 8:57
11) Metaphase II 9:23
12) Anaphase II 9:28
13) Telophase II 9:32

Want to see Hank play Assassin’s Creed? Check out http://www.youtube.com/hankgames
Watch the AC: Brotherhood playlist here: http://www.youtube.com/playlist?list=PL0B3CD662A033D273
Watch the AC: Revelations playlist here: http://www.youtube.com/playlist?list=PLC5C810D94ADB2080

reproduction, sexual reproduction, sex cell, sperm, egg, meiosis, crashcourse, crash course, biology, cell replication, chromosome, gene, allele, homologous chromosome, haploid cells, prophase, metaphase, anaphase, telophase, oocyte, spermatocyte, centrosome, microtubule, crossover, homologous recombination, natural selection, cytokinesis, polar body, endosperm

Islam, the Quran, and the Five Pillars All Without a Flamewar: Crash Course World History #13

In which John Green teaches you the history of Islam, including the revelation of the Qu’ran to Muhammad, the five pillars of Islam, how the Islamic empire got its start, the Rightly Guided Caliphs, and more. Learn about hadiths, Abu Bakr, and whether the Umma has anything to do with Uma Thurman (spoiler alert: it doesn’t). Also, learn a little about the split between Sunni and Shia Muslims, and how to tell if this year’s Ramadan is going to be difficult for your Muslim friends. Let’s try to keep the flame wars out of this reasoned discussion.

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Mitosis: Splitting Up is Complicated – Crash Course Biology #12

Hank describes mitosis and cytokinesis – the series of processes our cells go through to divide into two identical copies.

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References for this video can be found in the Google document here: http://dft.ba/-2rVV

Table of Contents

1. Mitosis 0:24

2. Interphase 3:27

a) Chromatin 3:37

b) Centrosomes 3:52

3) Prophase 4:14

a) Chromosomes 4:18

b) Chromatid 4:31

c) Microtubules 5:07

4) Metaphase 5:22

a) Motor Proteins 5:36

5) Biolography 6:13

6) Anaphase 9:00

7) Telophase 9:15

8) Cleavage 9:25

9) Cytokinesis 9:36

This video contains the following sounds from Freesound.org:

“Swishes.wav” by Pogotron

“Opening Scotch Whisky.mp3” by Percy Duke

crashcourse, biology, mitosis, cell biology, cell division, cell, replication, splitting, chromosome, diploid cells, nucleus, DNA, prophase, metaphase, anaphase, telophase, interphase, chromatin, chromatid, centrosome duplication, centromere, microtubules, motor protein, walter flemming, tomomi kiyomitsu, dynein, cleavage, cytokinesis, daughter cells, science, education, college, university, learn, teach, hank green

Fall of The Roman Empire…in the 15th Century: Crash Course World History #12

In which John Green teaches you about the fall of the Roman Empire, which happened considerably later than you may have been told. While the Western Roman Empire fell to barbarians in 476 CE, the Byzantines in Constantinople continued the Eastern Empire nicely, calling themselves Romans for a further 1000 years. Find out what Justinian and the rest of the Byzantine emperors were up to over there, and how the Roman Empire dragged out its famous Decline well into medieval times. In addition to all this, you’ll learn about ancient sports riots and hipster barbarians, too.

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DNA, Hot Pockets, & The Longest Word Ever: Crash Course Biology #11

Hank imagines himself breaking into the Hot Pockets factory to steal their secret recipes and instruction manuals in order to help us understand how the processes known as DNA transcription and translation allow our cells to build proteins.

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Table of Contents:

1) Transcription 2:12

A) Transcription Unit 3:00

B) Promoter 3:10

C) TATA Box 3:32

D) RNA Polymerase 4:12

E) mRNA 4:15

F) Termination signal 5:21

G) 5′ Cap & Poly-A Tail 5:34

2) RNA Splicing 6:08

A) SNuRPs & Spliceosome 6:26

B) Exons & Introns 6:56

3) Translation 7:28

A) mRNA & tRNA 8:01

B) Triplet Codons & Anticodons 8:39

4) Folding & Protein Structure 10:51

A) Primary Structure 11:11

B) Secondary Structure 11:23

C) Tertiary Structure 11:58

D) Quaternary Structure 12:44

Links to episodes referenced in the video:

DNA structure episode: http://www.youtube.com/watch?v=8kK2zwjRV0M

Animal cells episode: http://www.youtube.com/watch?v=cj8dDTHGJBY

Fold-it SciShow episode: http://www.youtube.com/watch?v=JdBcpdH_ptA

REFERENCES Read more of this post

Christianity from Judaism to Constantine: Crash Course World History #11

The Mongols Shirt is available for pre-order now! http://dft.ba/mongols

In which John Green teaches you the history of Christianity, from the beginnings of Judaism and the development of monotheism, right up to Paul and how Christianity stormed the Roman Empire in just a few hundred years. Along the way, John will cover Abram/Abraham, the Covenant, the Roman Occupation of Judea, and the birth, life, death and legacy of Jesus of Nazareth. No flame wars! Let’s keep the commentary civil.

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DNA Structure and Replication: Crash Course Biology #10

Hank introduces us to that wondrous molecule deoxyribonucleic acid – also known as DNA – and explains how it replicates itself in our cells.

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References for this episode can be found in the Google document here: http://dft.ba/-2hCl

1:41 link to Biological Molecules http://www.youtube.com/watch?v=H8WJ2KENlK0

Table of Contents:

1) Nucleic Acids 1:30

2) DNA

-A) Polymers 1:53

-B) Three Ingredients 2:12

-C) Base Pairs 3:45

-D) Base Sequences 4:13

3) Pop Quiz 5:07

4) RNA 5:36

-A) Three Differences from DNA 5:43

5) Biolography 6:16

6) Replication 8:49

-A) Helicase and Unzipping 9:22

-B) Leading Strand 9:38

-C) DNA Polymerase 10:08

-D) RNA Primase 10:24

-E) Lagging Strand 10:46

-F) Okazaki Fragments 11:07

-F) DNA Ligase 11:47

DNA, deoxyribonucleic acid, chromosome, nucleic acid, ribonucleic acid, RNA, polymer, nucleotide, double helix, nucleotide base, base pair, base sequence, friedrich miescher, rosalind franklin, replication, helicase, leading strand, lagging strand, rna primase, dna polymerase, okazaki fragment