Genetic Recombination and Gene Mapping

[@Tomozaurus]

I swear these videos are 100% times better than the actual lectures from my university-run units. They should just show these.

[@mack_raymond]

I have done the majority of my learning on KZbin, for free and in half the time as in lecture. Yet I am paying enormous amounts of money for tuition. This is sad. The only redeeming quality of the school system that I can find is that it pressures me into learning the material for exams. If I didn't have that pressure, perhaps I wouldn't be bothered to learn the material.

[@shadowkisss1958]

funny you mention that cause we are mostly put on to watch his videos in my grade 12 Biology classes

[@theongraham3394]

A million times better than my lecturer!

[@megha7564]

Tom Parker def

[@jessrider2711]

Agreed. I've already learned more from him in a week than this entire semester.

[@samaalnassiry7541]

I haven't watched Bozeman science since my senior year of HS AP biology class. Here I am, 5 years later in college watching him again. Thanks for getting me one degree and on the way to the second.

[@LXRY]

im in senior year ap bio right now lol. good luck on your next degree!

[@kirillkondrachov4864]

Exam tomorrow, and I now understand all of this. Bless your soul.

[@karinabuhaya5878]

good luck! hope u did well back then

[@fernsader9261]

​@@karinabuhaya5878 unfortunately he's not with us anymore because of this class

[@keishabencosme8491]

Same here

[@Jo-gj2nr]

It’s 1 AM the night before my AP bio exam, my bio teacher has spent the entire semester talking about her kids instead of teaching us, I want to thank you for being my bio teacher

[@steff4413]

Jo how did you do

[@joebangles9951]

We need to know, how'd it go

[@Jo-gj2nr]

@@joebangles9951 got a three lol

[@kurdweeb599]

@@Jo-gj2nr out of?

[@Jo-gj2nr]

@@kurdweeb599 5, so not so bad

[@hydrogenperoxide7244]

The fact that i understand more about the whole chapter in this 10 minute video than my one and a half hour of lecture is amazing

[@jsscmoran]

Dear Lord... i learned more in this video than in two lectures ...thank you

[@skennedy918]

I always use Bozeman science when I am stuck on something from a lecture at uni, helps me understand it in a better light and furthers my learning greatly.

[@zoemccall2473]

I was first introduced to your videos as a freshman in high school, during my neuroscience class, and now I'm a freshman in college and I still like coming back to your channel:)

[@lauramorganti4129]

Just wanted to say thank you. I watched this video the night before my genetics exam because I was so confused and I scored 100% 😂🙌🏼

[@whitakerhoskins]

B to A should be 15 map units

[@A169JB]

+Whitaker Hoskins thanks i did pause and i couldnt figure it out...

[@darrrenmk]

+Whitaker Hoskins Realistically you are right but the recombinant frequencies come from a sample which means there is a range of error

[@OShawna23]

Whitaker Hoskins why

[@thea16able]

Thanks I thought I was going crazy

[@sierraslyh6743]

so, when you look at the math behind the gene mapping, one would expect the distance from B-A and A-D to add up to the distance between B-D since A is just a point in between B and D. however, when you look at the numbers 30+25 does not equal 40. hope that helps

[@blessdog5392]

Blows off his homework. FIres up his pipe, and figures the whole thing out. Studivent was bad 2 the bone

[@sohoyankee66]

I'm running out and buying a pipe. Maybe then I'll understand this. :-)

[@crownofall]

Sounds like me only i prefer a cigarette

[@NobleVagabond2552]

Sounds like me right now except I’m just high af tryna study, all I’m saying tho, Alfred sparked the la

[@mayabalaji1020]

Mr. Anderson, Thank you so much for taking the time to post some of the most helpful science videos on youtube! Your time means the world!!

[@ShimiVa]

"and i hope that was helpful" yes, yes it was! way more than the 2 hours i had in class today! thanks!! you're amazing!

[@Tamang4CA]

for the last gene mapping part. if B to C is 45%, isn't it impossible for A - B (30%) and A-D (25%) to be bigger than 45%?

[@halamilktea]

A-B would be 15% right

[@azuretea7534]

agree

[@chickenwang8786]

yeah I noticed that also

[@r8irtyit664]

Ye...

[@pratibha2551]

i wish you well.7 years ago wow

This video helped me a lot. I just have to consider some issues about the distance of B-A and A-D. Thinking of it mathematically the distance between B-D from the given data is equal to 55 map units which on that note it should be independently assorted. It must have been 10 map units between A-D which would make total sense and the reordering of the gene map. I have to thank you Bozeman for letting us think critically and curiously

[@joshuawhittaker1233]

Your thinking is great, but in reality, his example is OK. It is possible (maybe even likely) there is a mistake and as a teacher he meant to give a simple example that added up nicely, but I think the numbers reveal the reality of genetic mapping. At 8:57 he says "relative map distance", because recombination frequencies accurately tell the ORDER of genes on a chromosome relative to one another, but do not always accurately tell the exact DISTANCE. In other words, sometimes the math doesn't add up. Reasons for numbers that don't add up are several. Double crossovers can result in incorrect distance calculations. Also, not all areas of the chromosome cross-over equally. Some areas are hotspots that have more recombination, and some areas like the centromeres have almost none. The farther apart genes are, the more opportunities there are for inaccuracy in distance calculations based on recombination frequency. Side note: Another obvious reason the numbers don't always add up, though not related to this exact problem, is that some human chromosomes are 200+ map units. This method can only calculate up to 50 map units because recombination frequency can't go over 50%. Genes that are over 50 map units apart on a chromosome will all map as 50% RF. In such a case, we would need more genes to compare that are closer together, or modern gene sequencing techniques. Also see Khan academy (bottom section of article): www.khanacademy.org/science/biology/classical-genetics/chromosomal-basis-of-genetics/a/linkage-mapping

[@Xelth4]

@@joshuawhittaker1233 why cant the distance of the chromosome be higher than 50 map units and the recombination frequency between 2 genes must ne lower than 50% ? Not even exactly 50? Why if it's exactly 50, it means that the genes are in different chromosomes?

[@AlmostAnything]

HELPFUL ? IT WAS WAS MORE THAN HELPFUL

[@rheannesantos458]

trueee

[@desertman33]

I've taken a number of courses with this concept and did well enough on the tests, but it was only as I watched this video that it really began to truly make sense

[@rev2505]

This less than 10 minute video just helped me understand what my teacher tried to teach me in a 1.5 hour lecture.

[@tomvolpe6562]

Great video! Two comments. 1) 50% recombination doesn't necessarily imply the genes you're mapping are on different chromosomes. The could just be far apart on the same chromosome or have a recombination hot spot between them. 2) When you discuss recombination between the b and vg you have a green box labeled recombination and red boxes above and below labeled no recombination. I know what you mean but students may think that there is no recombination occurring in these regions. It may be but you just can't see it with the alleles you are tracking. Thanks again for all your hard work making these videos. They are extremely helpful.

[@yvonnechiletmarch798]

yes it does, as a chromatic only represent 50%, so if its more than this is means its not in the same chromatid and therefore chromosome after recombination

[@rgudduu]

recombination is always checked pairwise, is it? Say, i want to find that final mapping of 4 genes a,b,c,d. So we do pairwise, taking 2 phenotypes at a time, and carefully choosing the corresponding flies?

[@Xelth4]

I didnt understand ur second one

[@sameepthakuri9550]

I guess studying at one of best university in the world doesn’t necessarily mean you have access to one of the best teachers in the world . Thank you for this

[@vasenainaiteqe7847]

I have my genetics exam tomorrow and this video has really help in thoroughly understanding Chromosomal Inheritance and recombination. Vinaka Fiji Islands

[@Tomteluva82]

most pedagogic teacher ever, awesome video

[@crosbywhittington4879]

Mr.Bozemen you are truly godsent. I stg you a single-handedly getting me through college science at this point. I hope your pillow is always cold on both sides.

[@amandashirley990]

The problem you give at the end does not make sense. If the correct order is BADC, as you state, the distance between B-A that you list as 30 mu, and A-D you have listed as 25 mu combined give a combined distance of 55, which would signify that the genes B & D are probably not listed on the same chromosome, and no where near the listed 40 mu's apart. I think the distance between B-A was supposed to have read as 15, not 30, in which case the problem is correct, and the idea that there are 40 map units between B & D is sound.

[@georgeofhamilton]

Arjune Giri Amanda Shirley Maybe he wanted to give us an example of an anomaly of statistics and make us see that this idea still works.

[@BrennanMohrer]

+Amanda Shirley Or maybe he just made a mistake. It happens.

[@noirritnibedita7565]

but I got BADC where A should be 10 units distant from D,here it is shown as 25!

[@dma67111]

noirrit nibedita no its 15mu Total 50mu..longest b-c 45mu So b-a + a-d + d-c (5%) = 45mu and on a 50mu chromosome

[@mouzicanat]

You can't combine the percentages. Assume they never relate in any way.

[@cosmiccaravan9408]

THOSE VIDEOS HAVE ACTUALLY HELPED ME UNDERSTAND AT ONCE ALL THE THINGS MY UNIVERSITY TEACHERS FAILED TO EXPLAIN CLEARLY! THANK YOU SO MUCH!

[@ztzexplorer]

A-B is 15 m.u., not 30. Your sequence of B-A-D-C is right though. But thank you Mr. Anderson. You're an amazing teacher. I use your videos all the time to reinforce concepts in the minds of my AP Bio students. If only I had your talent!

[@joshuawhittaker1233]

In reality, his example is OK. It is possible (maybe even likely) there is a mistake and as a teacher he meant to give a simple example that added up nicely, but I think the numbers reveal the reality of genetic mapping. At 8:57 he says "relative map distance", because recombination frequencies accurately tell the ORDER of genes on a chromosome relative to one another, but do not always accurately tell the exact DISTANCE. In other words, sometimes the math doesn't add up. Reasons for numbers that don't add up are several. Double crossovers can result in incorrect distance calculations. Also, not all areas of the chromosome cross-over equally. Some areas are hotspots that have more recombination, and some areas like the centromeres have almost none. The farther apart genes are, the more opportunities there are for inaccuracy in distance calculations based on recombination frequency. Side note: Another obvious reason the numbers don't always add up, though not related to this exact problem, is that some human chromosomes are 200+ map units. This method can only calculate up to 50 map units because recombination frequency can't go over 50%. Genes that are over 50 map units apart on a chromosome will all map as 50% RF. In such a case, we would need more genes to compare that are closer together, or modern gene sequencing techniques. Also see Khan academy (bottom section of article): www.khanacademy.org/science/biology/classical-genetics/chromosomal-basis-of-genetics/a/linkage-mapping

[@orangecaprinun]

It is customary to like your video before it even starts at this point, THANK YOU SO MUCH Prof!

[@faramund9865]

8:59 There's an issue now though because now B and A aren't 30% apart!

[@sashadecosta3537]

you get it! you have one the internet for today! congrats! hahah! holy cow what a mistake to have been made! omg, could never have been me!

[@emiliaarif]

whats life without paul andersen... thank u paul ^^

[@ladinonyc]

For someone like me. Besides reading the text book( which I don't get) to later watch a video.Your video helped give me a better image of whats been spoken about in class.Thank you.

[@lianafeng7074]

Mr. Anderson is my lifesaver every time 🙌🏻🙌🏻

[@Joelpenda]

Thank you Professor.You make things really simple and easy to understand.

[@itsmemargarette9836]

This is how you properly explain Genetic Recombination and Mapping. By watching this, I was able to FULLY understand it!! Bye Universities. LOL

[@UdyKumra]

The only thing I'm going to remember after the AP exam: if you blow off your homework you might make a groundbreaking discovery.

[@vanshpatel9461]

Udy Kumra usohy

[@MacyCathleen]

Don't know what I would have done without your videos and Khan academy this quarter! Thank youuuu!

[@leewonkim3533]

you are the uni lecturer we need but don't deserve

[@lancebryan56]

ive been watching these videos since 11th grade AP bio and they're even helping me now in my 2nd year in undergrad :')

[@farhanaahmed7163]

I was so confused in the lecture, this video has helped me so much, all your videos explain perfectly! Thank you very much!

[@Its2EZbaby]

Very helpful, thank you so much. 1000% times better than my college professors could explain over the course of several lectures.

[@SpycyWonton]

I understand the concept better now, thank you! The only confusing part was the math in the RF example, the numbers don't add up.

[@wearemarshall5240]

A and B should be 15 cM apart, not 30 cM

[@ryankelly328]

I agree that A and B should only be 15 map units apart. Otherwise A--> + B--> is greater than 50. Please add a text note to the video.

[@rehabfarid172]

yeah makes sence, so that B---A---D---C add up to 15+25+5=45 which is the distance between B---C

[@satinderjit4]

actually they are probability, not actual measurements

[@wearemarshall5240]

satinderjit4 , you are correct that they are measured in probability. A 'cM' is a centimorgan which corresponds to 1% probability.

[@jayliu7786]

Levi Marshall, I had the same thought as you had at first that they were actual measurements and not probability so I spent my time trying to group the genes together so they would total the largest distance. It's nice to know, this is a lot easier than that.

[@zogfotpik8848]

Man, this guy looks like Hank Green, and he lives in Montana also

[@Tinuviel-gv4xm]

+Jim Gibbs He is way better looking than Hank Green

[@richarddenny8013]

There related

[@richarddenny8013]

jk idk

[@jenniferwang946]

Tinuviel 19715 oooooofff

[@SirJaxxSirJaxx]

Wouldn't the range between A & B be 15%? Because if B to D is 40%, subtracting A's 25% should only allow 15 units left over between A & B and not the 30% you have listed.

[@kingfisher32]

I was confused by my teacher’s lecture today but now I understand the topic!

[@GodisGris1]

This was so helpful! I love that you actually used an example och how to solve it

[@katharina...]

All excellent teachers should be required by law to make youtube videos :D Thank you for your time Mr Andersen, your contribution is invaluable!

[@Sabibi420]

I was going over my lecture material for like an hour and was stuck on the recombination frequencies, I'd almost lost all hope until I found this video. You explained it all so well I can finally understand it now, thanks!

[@hebahamood362]

my HS teachers traumatized me by making us watch you all the time but I'm so glad I got over it! woohoo ty very helpful

[@jennifermccarty7272]

I am so thankful I stumbled upon your channel, this video in particular. My praxis biology content exam is coming up and your videos are a blessing!

[@aliyahstinard3038]

You made me understand in 10 minutes what my professor couldn't over 2 weeks

[@Pingyer]

I was wondering the internet for hours wondering how this works, and you somehow just flipped a switch in my head. Thank you😂

[@matthew_bang]

UC honors bio genetics class. Lectures didn't explain this and textbook didn't bother to explain either. You're my go-to source for bio videos

[@pris3675]

This is super helpful great job Mr Andersen! Sincerely student trying to pass HL bio

[@charityann27]

you and the amoeba sisters have helped me out a lot this semester

[@phillipkrayterman3008]

Actually just saved my life. You made a hard concept easy to grasp for anyone. Thanks!

[@tamaracoore6079]

i love your videos so much, it gives me hope, I've been watching them since my freshman year now I'm a junior taking genetics, you helped me through BIO1 and 2 now i feel confident about genetics. -Thank you

[@jorgeaguilar5809]

OMFG I hope one day I can be as skilled as you to teach science, your videos are GOLD :D

[@gazw9933]

Damn. Mr Anderson, you make some of the trickier aspects of my degree so easy to learn. Your videos are an asset to my learning. Thank you. And to answer your question. Yes. It was helpful 👍👍

[@cloverring]

OH MY GOG I LOVE YOU THIS SAVED ME! My teacher didn't go through this and just let us read the section on our own since it was only 2 pages but I was so baffled but the whole mapping thing!

[@raj10fat]

Explanation was crystal clear, understood the concept. Thanks Paul. Kudos

[@cosmiccrystaldreams]

Amazing video! Explained it in a way that was easy to understand and had excellent visuals to match. Keep more videos coming!

[@judyleatherman7563]

Mr Anderson, I am a genetics professor, and you have great videos, I appreciate you and like to provide additional resources like yours for my students to learn genetics! But you've got an error on this one--each chromosome is NOT 50 cM. The percent recombinants are not related to the full length of the chromosome. Some long chromosomes are 200+ cM, and once genes are 50 cM apart, they simply act like they are unlinked.

[@mashaelahmed1416]

why exactly arent u teaching at a top rated university ? my genetics prof. is the worst instructor anyone could have!! THANK YOU FOR THE VIDEOS!

[@FourtySven]

i feel bad for those fruit flies, everytime i make them in my green box i just put it outside and set them free

[@faz1991]

As soon as he said "Mr. Anderson" i thought of: "It's inevitable... Mr. Anderson...".

[@madcowzrchewy]

Thankyou for this! You're infinitely more helpful than the so called "teaching academics" at my university.

[@dan-simi6]

The percentages of A-B + A-D = 55% or should I say 55 u.m. Shouldn't = 40 % or u.m.? As the distance from B-D (40%) ........since A is between them hmmmm

[@rhettwilliams4996]

You just saved my grade for finals. Bless your soul.

[@husseinsa5050]

regarding the problem, I think the distance between A & C is 25% not between A & D. think youu

[@nancyjan25]

I hate my professor after watching this. She made it into an engineering class. Thank you for making it simple !

[@zujamongullie6544]

After watching Nth number of video on this. Finally I landed on this!!!! And it cleared all my doubt. I feel like I have attained enlightenment. Thank you so much sir

[@meggietiffany9124]

Thank you for being a more understandable source of teaching than my Actual university lecturers

[@medaphysicsrepository2639]

only criticism i have is that morgan and strutevant didn't know that DNA was the genetic material

[@nicholasdiederichs]

thomas underhill The amount of protein associated with the DNA in a chromosome is so vast (scaffold, cohesins etc...) that even to have suggested that DNA is the carrier of hereditary information in an era when proteins were THE got to functional biomolecules without the Avery and Griffith experiments would have been interpreted as a sure sign of madness!

[@jeranimo.gaming]

My professor said that the recombinations frequency of vg-cn is 9.5%

[@LK-cc4uj]

You are such a great instructor. The visuals were so helpful as well. Thank you!!

[@komals.6881]

Sir you are the best teacher for genetics i would say.. Your vedios have helped me a lot. Thank you so much.

[@drvir]

*videos

[@AsfandyarAfridi]

U are the best teacher ever ...U made me look good

[@Samanthava]

Absolutely brilliant mate. Clearly presented and you get right to the point I love it. Thanks for the contribution Paul. HD in gentics here i come :).

[@juliabeckers4349]

very helful explanation! question about the example though: if B and A are 30% apart and D is 25% from A how can B and D be only 40% apart. If you'd add those percentages you would have 55% out of 50 map units. am I doing something wrong? or is this example just not meant to be that accurate?

[@caitlinn8616]

I'm having the same problem and just asked the same question a few second ago. Hopefully someone answers it bc I'm also confused!

[@juliabeckers4349]

@@caitlinn8616 Heyy yea when I looked further down the comments I saw I wasn’t the only one. I figured it’s just an example and not meant to be accurate:)

[@ananyasuri1223]

Omg I don’t have words to explain about this video....I saw a lot and lot of videos but finally understood it .....thanks

[@clairetellkamp6253]

1) You are mapping over the centromere. We were taught that you can't map over the centromere because it is the strongest point. The rate of breaking off and crossing over increases to 50% toward the ends. 2) The example doesn't work. A-B would have to be 15% or A-D would have to be 10%. It doesn't work as you had it.

[@monagpal1842]

We watch your videos in IB Bio HL, and they help a ton! Thanks so much!

[@AkimboTimbo]

Noo you're saying it wrong, maybe for the comprehensibility of the video, but the recombination frequency (or map units) between the genes vg - cn was 9,5% , and not 8% . When you add up vg - cn (9,5%) and cn - b (9%) it comes to a total of 18,5% and not 17% !! Can someone please explain that 1,5% ?

[@alurusumanthkashyap8277]

Inspiring for all those who are trying to listen the classes and read books, not better than this ...

[@kenbessellieu8267]

Just in time for my final next week! Thank you so much, I owe my A in Bio this semester to you! :)

[@CORPSE77]

this is way more useful than any textbook

[@rituraj1999]

It's really true he is way better and interesting to listen than university professor.

[@marie-carmenloyo6266]

You, sir, are going to heaven. Thank you!

[@funnibunni500]

Way better than my crappy genetics teacher at school. Thank you!

[@carlettagoodrichmann1513]

Combined recombinant genes. Sample size the chromosomes. Mutation of genetic evolution.GENETEC Stem cells. The catalogs of Nuclear medicine.

[@konstantinospanagiotopoulo2927]

Thank you Paul! I was looking for an explanation like this one! Great work thanks again :)

[@hainguyenthanh5055]

Just curious. If A between B and D so AB = 30% = 0.3 AD =25% =0.25 -> BD = 0.55 it is different what we got in the box. 0.55 for BD and 0.4 BD in the box please explain

[@blueblood-_-]

I also have the same doubt.

[@Antweezy]

bless you. this was so much easier to follow than an hour long lecture

[@alexbjjperez]

Making dummies like me smarter thanks this really helped me out for my genetics class.

[@nancysohlberg8150]

Thank you so much! This illustration and connection is EXACTLY what I was looking for!

[@iayushanand]

Why only two chromatid involve in crossing over? Wny not all four chromatid (2 pair of non homologous chromosome) cross over at same locous to give 100% crossing over.

[@jacobmarks2868]

The best video on KZbin

[@nmss9969]

Thank you for all the biology videos! They are excellent and so helpful.

[@Vreezy77]

I'm pretty sure that the math on that practice problem should be reworked. I get that these numbers are relative, but If B-D is 40 and A-B is 30 then A-D should be around 10, but the problem says 25....?

[@Dnjeb]

when i red the txt book, i was confused, when i had a lecture, i was in chaos when i watched this vid, i was fianlly enlightened.