omg XDD my voice isn't that cute, it just sounds vastly different on camera compared to IRL lol But anyways, glad to hear that the videos help and thanks for watching! :D
It's ok!! Your own revision will be good to begin with, my videos are hopefully just things to help you along :D All the best tomorrow and paper 3 and thanks for watching!
I'm about to upload a video covering 20.3-4 on dihybrid inheritance and a bit on unexpected phenotypic ratios, so perhaps you'll find that helpful! :D It's hard to tell what kind of Qs will come up on this part - but the key thing is knowing that phenotypic ratios can be different from our expected ones from Punnett squares due to random fertilisation and autosomal linkage (so genes get inherited together as "one unit", rather than independent from each other). And we can confirm that by doing a chi-squared test. Hope these videos will help! Feel free to comment below that video and I'll answer that to clarify if need be :) Thanks for watching!
I do plan on covering the whole spec, but I may not have time to covering Ch.14 before this year's exam, sorry... :( But hopefully the other ones will help still! Thanks for watching!
Hi, sorry if this is a silly question but at 14:56 do you mind explaining the reason why the probability isn't 25% (1:2:1) since it is monogenic heterozygous.
there are only 3 possible combinations for sex linkage. for the recessive allele to be expressed, the allele pair must be homozygous. 1/3 are homozygous. making it 33%
Exactly this. We can't just consider the "usual" monogenic inheritance in sex linkage, as we need to consider the combination of the sex chromosomes first.
Yes the formula would be given! The stats equations would always be given. Have a look at the OCR Maths handbook to see what equations would be given and what you need to memorise. Or check out the Maths playlist here: th-cam.com/play/PLcqmJII16GiCvYmhqMYpuzqXKdK_W-cjW.html
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Every one of your videos is crazily good 🥰 I would have no chance at OCR biology without you, thank you!!!!!
The worst topic in module 6 in my opinion, you're videos make everything seem doable. I especially loved the cloning and biotechnology ones 😍
Do you think in comparison to previous years will people do better or worse in Biology A level?
@@whiteboy4226 probably worse based on how things are in my school.
@@nviscallin3702 thanks, just interesting to hear what other people think.
Glad to be of help! :)
I agree it's huge and a lot of similar and confusing concepts. I'm glad Paper 2 grade boundaries are very low, you needed 48/100 for an A in 2021.
Thank you so much - I was struggling on the sex-linkage part and you cleared it right up!
I love your videos and your voice is so cute, I have to literally force myself to focus on what you’re saying instead of just listening to your voice
init.
omg XDD my voice isn't that cute, it just sounds vastly different on camera compared to IRL lol
But anyways, glad to hear that the videos help and thanks for watching! :D
@@BioRach too humble too humble.
Lmaoooo
Why did I find about u a day about the exam!!!!!!!😭
It's ok!! Your own revision will be good to begin with, my videos are hopefully just things to help you along :D All the best tomorrow and paper 3 and thanks for watching!
This was so helpful thank you! Do you do any videos working through past paper questions?
Thankyou so much. This has SAVED ME
Really useful the extra stuff on this is really good too thank you so much
Your videos are amazing; very useful. Thank you!
Thanks so much literally saving my a level
Thanks for the helpful video! :)
If possible could you please do a video on autosomal linkage (chapter 20.4) as I find this topic really confusing.
I'm about to upload a video covering 20.3-4 on dihybrid inheritance and a bit on unexpected phenotypic ratios, so perhaps you'll find that helpful! :D It's hard to tell what kind of Qs will come up on this part - but the key thing is knowing that phenotypic ratios can be different from our expected ones from Punnett squares due to random fertilisation and autosomal linkage (so genes get inherited together as "one unit", rather than independent from each other). And we can confirm that by doing a chi-squared test.
Hope these videos will help! Feel free to comment below that video and I'll answer that to clarify if need be :)
Thanks for watching!
@@BioRach Thank you!
Brilliant video as always, thanks :D
Glad it was of help! :D Thanks for watching!
BioRach Hey again, any videos on genetic engineering or gene therapy? Thanks
type O blood: i o i o
me: its off to work we go!
Yes 👍
Thanks for watching :D
Hav u don a video on coordinated responses?? If u havnt please do, it would be so helpful. Thank you
I do plan on covering the whole spec, but I may not have time to covering Ch.14 before this year's exam, sorry... :( But hopefully the other ones will help still! Thanks for watching!
Hi, sorry if this is a silly question but at 14:56 do you mind explaining the reason why the probability isn't 25% (1:2:1) since it is monogenic heterozygous.
there are only 3 possible combinations for sex linkage. for the recessive allele to be expressed, the allele pair must be homozygous. 1/3 are homozygous. making it 33%
Exactly this. We can't just consider the "usual" monogenic inheritance in sex linkage, as we need to consider the combination of the sex chromosomes first.
thank you fir this, it is hard to fin a monogenic inhertance video cause all I saw is Polygenic inhertance
thank you for this
Glad you find it helpful! Thanks for watching :)
Is chi squared formula given in the exam in a table format as all the past papers I have done they are?
Yes the formula would be given! The stats equations would always be given. Have a look at the OCR Maths handbook to see what equations would be given and what you need to memorise. Or check out the Maths playlist here: th-cam.com/play/PLcqmJII16GiCvYmhqMYpuzqXKdK_W-cjW.html
ty
correct me if im wrong so a homozygous cross is always a cross be homozygous dominant x homozygous recessive e.g. RR x rr ?
They'll never define the crosses as such - you'll always be told what genotypes/phenotypes you're crossing.
awesome
Hi, do you work through autosomal linkage in your videos anywhere please? Thanks
Here! th-cam.com/video/FYw2F0uku_Q/w-d-xo.html
@@BioRach Thanks
Hello creator, can I ask what word did you say on "rather than having a ...." On -13:27 onwards
rather than having a 50% chance to be recessive