The Sordaria Cross

In this video Paul Andersen shows you how a cross between mutant and wild types of Sordaria fimicola can be used to show and measure frequency of crossing-over. He begins by reviewing the process of meiosis in a typical organism. He then shows how crossing-over can affect the formation of sports in the perithecium of the fungi. He discusses the importance of frequency of crossing-over in determining the distance between the gene and the centromere.
Intro Music Atribution
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Artist: CosmicD
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Creative Commons Atribution License
All images are either Public Domain or Creative Commons Attribution Licenses:
"File:Drosophila in the Lab.jpg." Wikipedia, the Free Encyclopedia. Accessed April 21, 2013. en.wikipedia.org/wiki/File:Dro....
"File:Drosophila Melanogaster - Side (aka).jpg." Wikipedia, the Free Encyclopedia. Accessed April 21, 2013. en.wikipedia.org/wiki/File:Dro....
"File:Morgan Crossover 1.jpg." Wikipedia, the Free Encyclopedia. Accessed April 21, 2013. en.wikipedia.org/wiki/File:Mor....
"File:Sordaria Fimicola Perithecium (heterozygote) 40X.png." Wikipedia, the Free Encyclopedia. Accessed April 21, 2013. en.wikipedia.org/wiki/File:Sor....
"File:Thomas Hunt Morgan.jpg." Wikipedia, the Free Encyclopedia. Accessed April 21, 2013. en.wikipedia.org/wiki/File:Tho....
Jakov, derivative work: Overview of the Major Events in Meiosis. See Also Image:MajorEventsInMitosis.jpg Source: www.ncbi.nlm.nih.gov/About/pri..., 10:19 (UTC). MajorEventsInMeiosis.jpg. commons.wikimedia.org/wiki/Fil....
Marqua, J. Perithecium (German: Perithezium), July 2, 2006. Original drawing by J. Marqua (German: Eigene Zeichnung von J. Marqua), text removed by user:Strobilomyces. commons.wikimedia.org/wiki/Fil....

[@Professorbubblegum]

bless you for making this video

[@islamik8391]

thank you so much for the explanation !

[@huongpham1495]

That was really helpful.

[@rygalindo]

Thank you, Mr. Andersen. University of Texas student looking for Clairification going into genetics lab test.

[@gfbarbato]

Nice video... but, one correction (aside from the "data is" statement... "data ARE"). You do NOT divide %RF by 2 to get map distance because of mitosis (at about 6' 20"); one divides the number of recombinant products by 2, since only 1/2 of the Meiosis II tetrads are actually recombinant -- then divide by the total number of scored asci. The mathematical result is the same, but the reasoning is quite different.

[@sarayubalachandar53]

thank you so much ♥️

[@sturdyfrog3931]

Thank you so much omg

[@LuminousSpace]

VERY, VERY HWLPFULLLLL!!

[@Bozemanscience1]

I wish my middle name was Thomas. I drink your milkshake! :)

[@layicorn]

is this a [there will be blood] reference?

[@sevorg6544]

LOL

[@bockman55]

The AP Exam is on May 13th, that's like 2 weeks away!

[@Red-mo2uo]

Good luck

[@jakely5323]

Howd you do ?😂

[@DarkKnightofHeaven]

What would happen if crossing over doesn't happen exactly as planned and the color genes are split or if a mutation occurs and there's a color change that's not tan or grey?
Is it ever possible where those ratios aren't your only options where you could say get a 3 tan: 5 grey or something entirely different.

[@youhave3verything]

I can’t answer your first question but I can try to answer the second one. The ratios are what the expected results are, not a gurantee for what they will be. Basically like how if you flip a coin a couple of times you might get heads 100% of the time, but the more times you do it, the results will approach a ratio of 1:1. Similarly with this fungus, the ratio is being approached the more times it reproduces, not necessarily the guaranteed ratio of results.
Edit: fixed typo

[@ranimnaoum5952]

thank y a looot !! that was really helpful :) But the only thing that i didn't understand is What(s the purpose of this crossing over, i know that it's important for the biodiversity but how it works ?

[@victorpalomino449]

idk man be quiet how abt that dummy

[@Ray-jg1bw]

You're the boss, bozeman :D

[@zawerkomok7288]

If i could only swim in the sea inside your eyes.

[@thesimpsons1614]

Does your middle name happen to be Thomas?
My favorite Director's name is Paul Thomas Anderson

[@layicorn]

Quentin Jerome Tarantino

[@thesimpsons1614]

lol ;)

[@jelly_belly101_2]

tell me hats your motiveee f:ppp

[@MisterSwaginator]

First.

[@Dyenosoreusrex]

On an educational video? You're a nerd who watched these, let alone gets first on these?

[@jamieokeefe4231]

Back off the homie Blake.

[@CaptainAnytime]

I hate this class

[@impanthering]

Lmao