Solving pedigree genetics problems

Once you have a background in pedigree conventions, this video should provide you with the tools to evaluate a pedigree to determine if a given trait could be autosomal dominant, autosomal recessive, or X-linked recessive.

[@theshiddler1640]

Who else is studying for their genetics final?

[@williammcmacken933]

ha me

[@benbellino3596]

The grind never stops

[@thedisturbedsoul]

🙋🏻‍♂️

[@Escos4uce]

Biology 😔

[@alialtan129]

U have a final that's just on genetics ? You're so lucky

[@alexmurphy6345]

Your Better than my Teacher

[@SiouxScience]

+Alex Murphy Thank you.

[@snowyyocean]

Alex Murphy same

[@nathanferrarese6363]

you're*

[@micaeladempsey1120]

I'm taking my biology final soon and this video just saved my life! This was so helpful I've never been able to understand pedigrees until now

[@SiouxScience]

+Micaela Dempsey I'm glad I could help!

[@melissasobolik4894]

SAME

[@kimdaniel0405]

Thanks to your help, I can finally solve Pedigree Problems.

[@voxomnes9537]

Flat out amazing. I understand pedigree analysis in a way I hadn't before. Continue to pump out these comprehensive yet easy to understand videos!

[@doom4232]

Dang this video really helped me understand pedigrees! Thank you so much, every single explanation was on point and very detailed!

[@SiouxScience]

I try... the problem is when you make a little mistake and don't want to go through all the work to fix it... Thanks!

[@tebarakalawosi1339]

Thank you so much! this helped me a lot

[@SiouxScience]

I'm glad to help! You're welcome.

[@AshishKumar-ir5zy]

If any of the guys still have doubt then can send me question. Will clear it to you ! I AM FROM INDIA 😇

[@harrapanman621]

me too :)

[@aa_glue1572]

Where is X-linked Dominant? Anyway great vid

[@Vivalabam1994]

I'm not sure but wouldn't autosomal dominant diseases with reduced penetrance be able to skip generations?

[@SiouxScience]

+Danny H I just tried to cover some basics. You're right - there are plenty of other possibilities out there.

[@nicollecretu9711]

This video was extremely helpful! I had no idea what I was doing before and now I do. Thank you!

[@michaelu2562]

I failed my second exam for genetics, 1 is dropped so I could say I failed 1, I have to pass the next 2, my mistake is following the textbook and the PowerPoint my professor lectures on and filling her study guide is also a mistake, the only pedigree problem I learned to do was find what genotype the parents are (sex linked dominant, recessive, autosomal recessive autosomal dominant) , on the exam there were like 10 questions and they would ask if II-3 pairs with II-5 would their child have the disease, and simply because I was on a time crunch and never seen those types of problems I completely froze and yup..... so from now on I’m watching your videos and others to practice variety question set ups because if I’m new to a type of question I take my time to analyze it and exams are long and 2 minutes per question..l there was just no way out for me ...

[@SiouxScience]

I'm glad these helped! When you take the time to put everything together into a 10 minute video or less... you have to try to be as clear and concise as possible. Thanks!

[@michaelu2562]

@@SiouxScience yes and I understood a lot more from your short video than long lectures she gives us with no examples provided, then figuring new questions on an exam’s time crunch was awful but literally you’re a hero, thank you!

[@michellewilliams1439]

Genetics heaven!! Thank you for helping me understand

[@SiouxScience]

I'm happy I could help! You're welcome.

[@lazzy5173]

This video stands out form the other videos on pedigree simply because of the fact that every characteristic of each particular trait was specified. This significantly helps in solving pedigree questions of higher difficulty. Thank you very much SiouxScience !

[@SiouxScience]

Thanks for taking the time to comment. I appreciate the kind words.

[@wrkin90044]

Helped a LOT on half of my take home final!

[@SiouxScience]

+wrkin90044 Good! I'm glad I could help!

[@anthonyurdzik6405]

Thank you! This was very helpful!

[@jackdunne7659]

Really great vid man, earned yourself a sub and a goodnight kiss ~the king of fortnite

[@jacobmellick6207]

are you the actual king of fortnite wow

[@dm55]

I find making notes on this really helps to follow this video. Thanx. Very helpful.

[@SiouxScience]

I'm glad I could help!

[@shlxka7764]

why am i seeing this after my genetics test

[@SiouxScience]

Why am I seeing this three months late? Thanks for watching!

[@hahaok2713]

Thanks for this

[@cucump2344]

Love from Ethiopia ❤ Thankyou for the explanation .

[@osamaemran100]

Male baldness isn't X-linked it's autosomal --> affected by testosterone in males

[@deepdoshi7113]

Bless you biology monk!

[@SiouxScience]

Thank you!

[@RichardAK]

can someone please do a vdo on my youtube videos are much better than high school teachers

[@Leadwithlove654]

I personally found this to be helpful: 1. Determine whether its's dominant or recessive? How? Dominant is present in every generation while recessive skips generations 2. Determine whether it is autosomal or sex-linked? How? Autosomal affects both genders equally while sex-linked affects mostly one gender. More Notes: Wish You Good Luck.

[@SiouxScience]

I love the problem solving involved, to be honest. Then again, I'm a biology major and science teacher... Thanks for the TL:DW.

[@joker123344]

This sucks because the problems aren’t convoluted enough for my class :/

[@annelisefernandez515]

This video is perfect! I finally understand those tricky pedigree problems, thank you!!!

[@SiouxScience]

+Annelise Fernandez I'm glad I could help!

[@yu-nj9sm]

THANK U SO MUCH. I ACUALLY LEARNED BETTER THAN MY TEACHER. KEEP UP THE GOOD WORK. THIS IS THE MOST CLEAR EXPLANATION THAT I GOT

[@dacioana3310]

Thank you very much! helped a lot with my biology quiz!

[@lotownowentown]

Thank you for this video. My biology teacher is a nice guy and all but the way he explains things make zero sense, and I finally understand it.

[@SiouxScience]

I'm thriled I could help!

[@farhaanfidai3181]

made it soo easy...nice one!

[@SiouxScience]

Thank you!

[@leo-jamespetit-frere1536]

Best teacher ever....

[@SiouxScience]

Thanks!

[@merinej950]

So far very helpful. But for the question that ends at 8:15----- what's probability that II-1 and II-2 would have a 5th child w/ this disorder? I get that the heteros crossed gives 1/4 aa. But does it not matter that it's specifically asking for 5th child? How would/wouldn't answer differ if it asked for 4th child?

[@cadenfuchs4991]

It does not change the probability that they will have an affected child. If two parents have 3 daughters, then what are the chances their next kid will be a female. The answer is 50%. It's in the wording of the question you see? If the question was what are the odds a couple will have 6 daughters and no sons, the answer would be different.

[@Gabe.Santos1]

After missing two days of biology (Im a sophomore in highschool) I was completely CLUELESS on how to solve pedigrees. After watching this I understand them like no other. Thanks to you, I got 100% on my pedigree quiz. This video was great help.

[@SiouxScience]

If only more of my students would bother to watch the videos.... I'm glad to have been helpful.

[@Milistaier]

ghr.nlm.nih.gov/handbook/illustrations/xlinkrecessivemother I don't get the part where you're saying that X-linked recessive gene will always be passed by the mother to the son. If a mother has XB and Xb (carrier), and combines with a dad who has Y and XB (thus not a carrier), then the result combinations would be XB Y XBXB XbY XbXB In which case, the very first individual is male and lacks the recessive X gene. That's what I thought right away, so in order to clear up my suspicions I searched on google and found the link I gave you that shows how a mother doesn't always pass the X-linked recessive gene to her son. Please clear up my doubts D: Other than that, really great video, I learned a lot. Thanks.

[@SiouxScience]

Milistaier What I meant is that if a son gets an X linked trait, he received it from his mother. I didn't mean to imply that a male will ALWAYS get a trait if his mother is a carrier. Sorry for the mix up. The reason that mothers are the only ones that can pass on traits to sons is that males only have one X chromosome (that may or may not be recessive) that they receive from their mother. Dads always pass on their Y chromosome to their sons.

[@maryanbumathy4833]

unfortunate thing is that I could like the video only once.really helpful. thank u sooo much BiologyMonk.

[@SiouxScience]

It takes a ton of time to go through and make this sort of video, so I really appreciate the feedback! Thank you.

[@ozunu1437]

We would appreciate if you put more effort in the delivery of your sentences. Sometimes its really hard to understand what you're saying. This goes hand in hand with assuming that a certain piece of info is common sense or obvious. This thought would lead one to skip some steps and not explain them, leaving the student clueless and confused. 2:28 Example 1: ''...number one'' 3:00 ''carrier for this recessive trait or what?''

[@SiouxScience]

The video is quite old without an external microphone, so I know what you mean. If I remake these with new tools, I’ll be sure to focus on clarity. Some of the videos also assume some previous knowledge from other videos. Thanks for the feedback - I’ll comment again here if I ever get around to replacing.

[@titoflash1212]

Excellent!!

[@SiouxScience]

Glad you like it!

[@omcs8996]

Good video!

[@SiouxScience]

Thanks so much!

[@briantrujillo4255]

I must of looked at like 3-4 other videos on how to solve this. looked at andrew douch, did not get it. I looked at yours and i got it, thanks a lot. helps to dumb it down, thx

[@SiouxScience]

I'm happy to help - thank you very much for the comment.

[@rheapatel2078]

Why wouldn't the last example be an Autosomal dominant? I thought it doesn't skip a generation because one of the children is affected. Do both children need to be infected for it to be considered dominant?

[@rheapatel2078]

I believe it is Autosomal Dominant because in order for it to be dominant, at least one parent must be infected, which the mother is.

[@mychikbad]

In the last slide asking about what type of inheritance is shown by the pedigree, are you assuming that the father (I-1) is heterozygous for the affected allele? I assumed that he was homozygous dominant and the mother (II-2) is homozygous receissive which would produce heterozygous children that should not be affected. However, II-3 is affected. Which is why I'm confused.

[@SiouxScience]

+Chik I think that the trait (shown as blue individuals) MUST be recessive, as it skips a generation. This means that I-2 is homozygous recessive (rr). Since her son (II-3) has this trait, the son must have received this trait from dad, making him heterozygous (or a carrier, Rr). II-1 COULD HAVE been heterozygous or homozygous recessive. Since he didn't show it he must be heterozygous. II-2 must also have been a carrier to pass it onto III-1 and III-3.

[@mychikbad]

+BiologyMonk Ah ok thanks for clearing that up!

[@SiouxScience]

+Chik you're welcome!

[@yasintopcu4042]

I think you had better add the letters on the lecture while you are explaining! It would be more helpful. Thank you...

[@SiouxScience]

I appreciate the feedback. Sometimes as I'm going through and making a slide show with Punnett squares or pedigrees I get to slide 60 and think wow - this is taking a while. That may help clarify though.

[@andreiangoluan9257]

I love how it is explained well. Can we please have or share your powerpoint presentation sir? For my reporting huhuu. Kindly help this poor medical student pleaseeee

[@SiouxScience]

docs.google.com/presentation/d/1kDceozbZL6GCZ45bhjpEDUqaxgS0Sm114B65PaMKJ3Q/edit?usp=sharing

[@jihanejiji8576]

well done but sometimes there is a probleme they really don't give us any clue .. for me the main problem is to make the difference between a auttosomal recessive or an X linked recessive that is really heard ..

[@SiouxScience]

What you USUALLY find with X linked recessive traits (male pattern baldness, red-green color blindness, hemophelia) is that males get them. You're right though - sometimes it can be numerous types of inheritance... and then there are polygenic traits, X linked dominant traits... endless other complexities.

[@milamary2164]

Really cool vid. Explanations are really clear and consistent. Love your work.

[@SiouxScience]

+Lexi Mary Thank you! I appreciate you taking the time to comment.

[@李欣然-e8t]

big question, how can u tell anything from a pedigree if every individual is affected?

[@SiouxScience]

You probably can't. You'd need a larger pedigree where some individuals are not affected and see what happens to their offspring. Pedigrees require you to find an example of what COULDN'T work.

[@southpoleelvs]

This is awesome! thank you so much!!

[@SiouxScience]

I'm glad I could help!

[@Dazzletoad]

A small correction. 'Hypocholersterolaemia' is low levels of cholesterol in the blood.' The dysfunctional genetic condition you refer to is familial hypercholesterolaemia 👍🏻

[@SiouxScience]

Whoops, thanks for the heads up!

[@Dazzletoad]

@@SiouxScience Any time 🤭👍🏻

[@markuswl]

Isn't autosomal dominant inheritance with reduced penetrance more probable in the last pedigree?

[@SiouxScience]

+Markus I just wanted to cover some of the more common types of inheritance - reduced penetrance is not something I cover specifically in my high school biology classes. Thanks for the comment!

[@jassitandon4592]

Can’t the autosomal dominant trait skip a generation if both parents are heterozygous and all their kids happen to get a recessive allele from each parent?

[@SiouxScience]

They can't skip generations. If you have one copy you show the trait. Like some forms of dwarfism, if you're homozygous dominant it can result in death.

[@devinsomekindathing4683]

I have watched so many videos about pedigrees and I only understand this one thanks!

[@SiouxScience]

Thanks so much!

[@mor9361]

Thank you! The most helpful video about this subject

[@SiouxScience]

I really appreciate it!

[@mitchellewilliam6190]

It was helpful for my cbse bio board exam 2016

[@SiouxScience]

+Mitchelle William I'm glad I could help!

[@sab8249]

Extremely informative! Thank you for simplifying inheritance and pedigrees.

[@SiouxScience]

Thank you! I'm glad I could help out.

[@kaorii1577]

Thank you so much this is by far the best video on YT about this topic, well at least the basics of it

[@SiouxScience]

Thanks so much for the kind words!

[@sowmiyav9859]

Isn't Tay Sachs disease an example of incomplete dominance

[@SiouxScience]

I think that this is autosomal recessive. Many individuals of Jewish ancestry get tested for this because if both parents are carriers their children can end up with the disease.

[@GiAndrei97]

Clear, clean, and right to the point, wish there were more professors like that. I've only had a few who are right to the point in a very straight and organize fashion! Thank you!

[@SiouxScience]

Thanks so much for the kind words! I find that making a video cuts out all the nonsense and just gets right to the point. When I'm actually teaching, there is some mumbling and stumbling involved...

[@ApurvaPopat]

thanks a lot

[@jewelnicolereaso3396]

It doesn't make sense that the last pedigree you showed is autosomal recessive.. Technically it didn't skip a generation, it was just not present in 1 out 2 of gen 1's offpspring. which means it is still present in that generation..

[@tarb92]

great video! with tay sachs though can you assume the mother would be heterozygous? Couldn't she be homozygous dominant?

[@charankoyaguri668]

you sound like the youtuber casually explained

[@SiouxScience]

I'm scared to check it out... thanks?

[@manalmalik2691]

Thank you that was really helpful!, Regarding the final example. Would it not be autosomal dominant as line 2 male 3 is affected?

[@SiouxScience]

Thanks for the kind words! For the final example, neither parent (II-1 and II-2) have the trait, but their kids do. This means it can't be dominant - unless there is a mutation.

[@manalmalik2691]

@@SiouxScience but line 2 male 3 is affected and is second generation? So would it make it autosomal dominant? Sorry I am confused

[@SiouxScience]

@@manalmalik2691 If you can find a SINGLE EXAMPLE of something there... then skipping... then showing up again, it must be recessive. You're trying to find an example that proves something couldn't be, if that makes sense.

[@gabedaniel3375]

thx... i need to get an 85 on this to pass the class. final is tomorrow.

[@SiouxScience]

+Gabe Daniel Did you pass?

[@augustinatorubiri2168]

❤

[@johneldho4434]

Where is the x linked dominant

[@SiouxScience]

+john eldho Sorry, I just tried to cover a few of the basics . I'll try to add this to another video.

[@Andyzup69]

That last pedigree is incomplete penetrance not AR

[@SiouxScience]

I think of pedigrees as a means of ruling out different forms of inheritance. Sometimes more than one could apply. I definitely didn't cover every possibility. Thanks.

[@juandicamayo]

how do you know the pedegree skips generations?

[@SiouxScience]

What you'd see is that one row (like the top row, grandparents) have some particular trait. The next row (middle row, parents) don't. The third row (children) do.

[@57udymu51c]

Thanks really appreciate your work

[@SiouxScience]

So nice of you. Thanks!

[@sabyasachibanerjee4816]

A big doubt got crystal clear. ........

[@SiouxScience]

sabyasachi banerjee Great! I'm happy to help.

[@Yaw_Kelvin]

great explanation. thanks alot Prof

[@SiouxScience]

Thank you! I hope it was helpful.

[@mohsintaj935]

I am preparing for NEET and it's very helpful ......thank u for this video sir

[@RandomVidz2468]

What about X-linked dominant?

[@SiouxScience]

I just selected a few of the most commonly discussed type of inheritance. This is certainly not a complete list of patterns of inheritance!

[@diygal5708]

This helped sooo much, Thank you

[@SiouxScience]

I'm thrilled I could help!

[@backstreetfan2887]

great video, I have subscribed

[@SiouxScience]

Thanks so much! I'm glad it helped.

[@annawestwood3081]

Really helpful. Thanks a bunch.

[@SiouxScience]

+Anna Westwood You're welcome!

[@jamesfive6429]

I watched many and this is the best one yet thx man.

[@SiouxScience]

Sorry for the delay… summer break. Thanks so much for the kind words!

[@Dippa1991]

What about x linked dominant?

[@SiouxScience]

There are just a ton of different patterns of inheritance out there. I just focused on some of the most common that end up on tests and quizzes.

[@TrueCourse]

Minor correction on 1:25 - stated "HYPOcholesterolemia... or genetic HIGH cholesterol." Should be "hypercholesterolemia" for genetic high cholesterol. Nevertheless, great presentation. Thanks very much for taking time in putting this together! :)

[@SiouxScience]

+TrueCourse Whoops! Thanks for the heads up. I'll take a look at that and try to get things fixed!

[@HafizahHoshni]

thanks a lot Sir 😀

[@SiouxScience]

You're welcome! I'm glad I could help!

[@UnorthodoxChildren]

Great video! THanks

[@SiouxScience]

+Don't Frown Thank you!

[@emilydavidvlogz1980]

I'm in med school and this video just saved my life. thanks haha

[@SKedu18]

THANK YOU SOOO SOO SO MUCH!!! took notes of everything you said! and understood everything after listening to it only once!!! Keep up being an awesome teacher! Lucky students though! :D

[@SiouxScience]

dreamscometrue Thanks so much!

[@jdsouthall7]

Hey, there I have watched you video and a couple others. This is my first year of biology and I really am trying to understand it. The question we have is:A woman has a disorder, but her husband does not. The disorder is inherited by half of her offspring, both male and female. Her children marry spouses who are normal. Of her daughters who have the disorder, half of their children also have the disorder. Of her sons who have the disorder, all of their daughters have the disorder, but none of their sons inherit it. The most likely mode of inheritance for this disorder is ________. I believe the answer is sex-linked dominate but then again could it be autosomal-dominant? Please help?????

[@SiouxScience]

I think it would be X linked dominant - not covered in this video. That doesn't mean it would HAVE to be - just the most likely cause. Thanks for the comment!

[@kosiokoye2384]

thank you so much... this helped alot... I had an assignment to submit and I had no idea about this pedigree... ur video was very helpful

[@16piecemcnuggetmeal18]

i literally cannot thank you enough. this was so helpful, and I'm one to learn slower and take more time to understand

[@SiouxScience]

My pleasure! Making a video you can pause... I need to make things as clear and concise as I can. I'm glad to help!

[@abasstemitope215]

Really helpful Thanks 🙏

[@SiouxScience]

Glad I could help! Thanks for watching.

[@carl___________]

What confuses me is that at times I feel as if a pedigree could be both autosomal or x-linked. As in, sometimes the pedigree doesn’t have something to differentiate the two. Like both ways it makes sense, so idk. Anyways, I think recall you saying that these problems aren’t meant for you to prove something but rather disprove something. Overall, great video, I understood and learned a lot :)

[@SiouxScience]

Sometimes it COULD be more than one type of inheritance. You try to eliminate options, but sometimes can't. Key things to look for would be males disproportionately having a trait over females.

[@emilie6466]

I have an AP bio exam in 2 hours and I have no idea what’s going on

[@SiouxScience]

I hope it went well!

[@emilie6466]

BiologyMonk thank you it did

[@richard_darwin]

Great video, but one thing. You just did one example for how to tell if a pedigree is x linked or autosomal and recessive or dominant. That example was perfect, because it had an affected mother with an unaffected son and a generation skipped. This showed that it was obviously recessive and autosomal, but I wish you had shown scenarios that did not have this.

[@SiouxScience]

I get what you're saying... the issue is that can confuse people even more. Thanks!

[@ME96.]

Wonderfully clear, thank you!

[@TheKpower123]

Are u signle

[@SiouxScience]

Thanks for the kind words!

[@russ117044]

What about is Crohn's

[@SiouxScience]

I don't think there is a specific, known cause for Chron's disease. It may be an autoimmune sort of thing, but not so "simple" as a genetic disorder controlled by one gene. Sorry I can't help more!

[@jonathanaugustin647]

I'm confused, why do you assume that the trait is homozygous dominant? How do you know the dad isn't homozygous recessive and the mom isn't heterozygous dominant?

[@SiouxScience]

I don't know which example you're talking about for certain - if you let me know the time you're looking at when watching the video I'd be happy to try and explain. Thanks!

[@festonbarnabas2014]

Most complehensive

[@festonbarnabas2014]

comprehensive

[@manikumari07]

Thank you very much

[@SiouxScience]

+Kumari Mani You're welcome!

[@surendrachauhan3041]

Thank you so Much for that video bcoz it that make easy pedigree understanding

[@SiouxScience]

+Surendra Chauhan You're welcome! I'm glad I could help.

[@rl5190]

Can you not get x-linked recessive carrier mothers having unaffected sons?

[@SiouxScience]

If you have a X-linked carrier mother, you should expect half of the sons to have a trait, half to neither have NOR carry it.

[@bradleylover166]

You're too legit to quit

[@SiouxScience]

+Fuzz Fuzz Hey, hey!

[@anjupandey8706]

Thankyou so much💫

[@SiouxScience]

Welcome!

[@intellexual9097]

Infinitely helpful video. Thank you very much!! :)

[@SiouxScience]

I'm happy to help! Thank you!