A2 Biology - Dihybrid inheritance + Unexpected phenotypic ratios (OCR A Chapters 20.3-4)

[@deets1250]

BioRach is the reason I can sleep peacefully at night.

[@BioRach]

haha glad you find the videos helpful :) Thanks for watching!

[@emmawilding9484]

literally. watching this at 00:24 because i have a quiz on this tomorrow morning and completely forgot to take the notes...

[@72jameskay]

@@emmawilding9484 I’m literally watching this because I have an A Level tomorrow :/

[@emmawilding9484]

@@72jameskay ah good luck, i got it behind me last year but i'm sure you'll do great and life definetly gets better haha

[@72jameskay]

@@emmawilding9484 cheers😎

[@TreeHive]

Whoever disliked... shame on you! Best bio teacher you can have :))

[@BioRach]

Aww thanks Leo XDD Rest well tonight!!

[@archibaldwilliam709]

Hi, Just wanted to come back and say a massive thank you! I managed to get an A in Biology this summer! Please keep making videos for others as they are SO helpful. Thanks :)

[@BioRach]

That's great to hear and thank you so much for letting me know! :D I'm glad that your hard work has paid off, well done! Thank you for your encouragement - I really appreciate the support :) All the best for whatever is next for you and thanks for watching!

[@RB-nh1om]

how did you get the A??? can you give me some tips. when did you start doing past papers?? how much did you revise perday??

[@darkmusky9851]

Thank you so much, these videos on Biology maths have put my mind at ease, the books couldn't explain it very well but you are a legend at explaining!

[@BioRach]

haha yes the book isn't always straightforward! I'm glad the videos helped you :D Thanks for watching!

[@libertyelliott9652]

This topic is so hard these videos have saved my life 💔

[@erin6184]

Just wanted to comment saying thank you for these videos , they are so helpful !! Thank you so much

[@BioRach]

Aww thank you! :D Glad you find it helpful! Thanks for watching :)

[@ayeshaa44]

Hi! Would you make any videos on OCR Biology Practicals please?

[@BioRach]

Good idea! Added onto my list :D Thanks for watching!

[@deets1250]

Also would you mind making a video on validity, reliability, etc btw you’re a legend ✨

[@BioRach]

Added onto the list! Thanks for the suggestion!

[@deets1250]

BioRach yayyyy

[@beyazitdurdu7524]

This woman is a legend

[@abrahimsharif8544]

Your Videos are next level!!!! keep up the Good work and thanks.

[@BioRach]

Thank you! All the best with your revision and thanks for watching :D

[@stephenloc6485]

I LOVE THESE. made life easier. When can you do the rest of this chapter?!!!

[@BioRach]

Haha glad you found the videos helpful :D I am aiming to cover the whole spec but it does depend on the time I have to make these videos (which is very limited!). Please be patient in the meantime and check out the other videos for now! :D thanks for watching!

[@stephenloc6485]

BioRach THANK YOU, I have almost finished everything!

[@ashleywong9185]

Thank you so much, Rachel! This really helped :) Can I have a request if you could do crosses on epistasis and autosomal linkage? Thank you so much!

[@BioRach]

Glad you found it helpful :) I'll put it onto my list, thanks for your suggestion and thanks for watching!

[@l.o3223]

Great video! Is it possible for you to make a video on epistasis and the different types as well as how it works? For example, is complementary epistasis not the same as recessive epistasis since the presence of two recessive alleles on the epistatic gene prevent the expression of the hypostatic gene?

[@BioRach]

Added on my list :)

[@ellamountain3087]

Saved my life thank you

[@safiyahmia116]

Love your videos, only way I understand this subject, would you make a video on plant hormones in Module 5 please x

[@BioRach]

Glad you find it helpful :) the hormones topic is on my list, as I have got a lot of requests on it! But I might not have enough time to get it out soon, so hopefully the others one help for now...! Thanks for watching :D

[@isabelokeke6255]

So helpful 💯😊, could you make a video on plant and animal responses ?

[@BioRach]

Yes that's been added onto the list! It's rather requested as well :) Thanks for watching!

[@rukayyasaifuddin6811]

Hey have you made a video on Epistasis and its affects on crosses? Pleaseee do so

[@BioRach]

No I haven't, because I wouldn't have enough time to plan and film another one before paper 1 (and actually the other papers)... So what I did instead was just covered the key points about epistasis and the interpretation of chi-squared test in this video and also in the A2 maths video. Hope they would help! Thanks for watching :)

[@Lyonpanda]

I'm sure you have had many requests already but I was wondering if Plant Hormones or a Liver video might be coming soon?

[@BioRach]

I am planning to cover the whole spec, but it'll take me a while to finish that! Those two topics are well requested so they are near the top of my list :) so hopefully the other videos will help you in the meantime... All the best with revision and thanks for watching! :D

[@brijeshpatel6772]

Just to let you know this playlist is not on your channel homepage under A2 heading.

[@BioRach]

Ooh thanks for letting me know! Will add it onto the A2 homepage :D

[@isabelcripps3979]

Honestly may god bless you, your a life saver!!

[@vmcnamara2391]

Excellent videos. More please and thank you in advance. Vivien

[@BioRach]

haha thank you! I'm glad you find them helpful, thanks for watching :D

[@wolfgangamadeusmozart1816]

I had a question: Are the 4 different gamete possibilities as a result of independent segregation and crossing over? Because if you model it such that the gametes YY and yy sit directly under RR and rr during meiosis, then the only possible combinations at the end of meiosis 2 are RY and ry. Is it purely as a result of independent assortment and cellular synapsis (chiasmata) that these 2 other possibilities are present?

[@Ok-cq7zq]

could u please make a video on rates in biology? i struggle so much on knowing what i need to divide by or times by and some rates questions are quite hard. thanks

[@BioRach]

Have a look at the "Maths in Biology - Basics" video! Rate is covered in that :D kzbin.info/www/bejne/eJPZoqegnrapi80 Thanks for watching!

[@arshiyakharel8561]

For dihybrid inheritance is it right to say the gametes carry 2 different genes and for autosomal linkage is it right to say that crossing over of gametes stops autosomal linkage from occuring? Love these videos btw thankyou ! :)

[@emanuelzachariah312]

Thanks big up I've understood more✌✌💪

[@martynaborisenkova8723]

Thank you! Your videos are so helpful!

[@MagicSecretsandMysteries]

Thank you so much for these videos... 🙌

[@amydoherty8222]

Do you have a video on epistasis?

[@BioRach]

No I haven't made one yet, but epistasis in a nutshell is gene interaction, about how the expression of a gene depends on the presence/expression of other genes. Dominant and recessive alleles interaction is already an example of epistasis. Hope this helps, and thanks for watching :D

[@RB-nh1om]

does dihybrid inheritance show the polygenic inheritance????

[@mysteriousmind5264]

You're soo..........good

[@my11account222]

Hi can i ask if i will cross BbCcDdEe x BbCcDdEe. How many: a. heterozygous pairs in the female parent b. gamete genotypic classes of the male parent c. progeny phenotypic classes d. progeny genotypic classes e. number of possible combinations of gametes

[@RB-nh1om]

isn't heterozygous cross In monogenic 3:1

[@fatimaal-nashi4381]

What's a genome ?

[@BioRach]

All the genetic material within the cell :)

[@dan33yandrew]

Anyone else have a patterns of inheritance exam tomorrow? 😰

[@fengtaii792]

Thank you teacher is it 9700

[@amalikimran]

UU SAVE ME DHAHEHAHHAAH