Hi Jesse! Just want to comment that as an international GAMSAT tutor myself, I found your channel to be inspirational in terms of content, format and techniques reviewed. Thanks for doing such a great job! (Regards, David.)
Another amazing video! I cannot tell you how fantastic these videos have been in helping me prepare for the GAMSAT coming from a non-science background! The resources and checklist are also INCREDIBLE - you're out here doing God's work - THANK YOU!!!!
Killing it once again with the great content, these videos are so good for revision or when stumped by a topic that i don't have time to review a textbook with. Thanks a million!
I loved the content of the video. I found the question very hard tho and actually barely understood it. Hopefully with more revision and practise, I’ll be able to get it✨
Hi Jesse! Can you explain what you mean in Q4 when you say "we don't need to multiply by half here (to account for sex ration) as the combinations of X's and Y's already cover that"?
wow I really appreciate you taking the time to upload these videos, I am sitting the gamsat in March and am finding your videos so useful. Can't thank you enough!
Hey thank you for the videos they have been amazingly helpful for study :) Not sure if I misunderstood Q4. It asks the chance of producing an orange female cat. Wouldn't the female cat always inherit the o from the male (as cannot inherit y) and either the O or o from the female making the probability of Oo occuring 1/2 which is then multiplied by the probability of 1/35000 to produce 1/700,000. Hope this makes sense, please let me know if I have interpreted the question incorrectly.
Hey there, glad to hear they're helping! So if it were to be certain or known for a fact that the offspring were a female then yes, there would be only two possible outcomes of equal chance Oo (orange with mutation) or oo (non-orange) HOWEVER The sex of the offspring is also a probability event so although there are two possible female outcomes, there are also two possible male outcomes, making four equally likely outcomes. The sample space of this set of outcomes is shown in the diagram I draw out at 40:06 Another way of thinking about this question is satisfying a series of sequential independent events (to use some probability jargon if you're familiar). in this case the question can be though of as "what's the probability that the cat is Female (event 1) AND it is a female carrier Oo (event 2) AND it has the mutation (event 3)?" This would be the product of each of their probabilities Pr(event 1) = 1/2 Pr(event 2) = 1/2 (using your method by only considering female outcomes) Pr(event 3) = 1/350000 Pr(event 1 & event 2 & event 3) = 1/2 x 1/2 x 1/350000 = 1/1.4mil
Very well organised detailed presentation. I really enjoy it but I think I need to watch it again and again to get the whole scenario perfectly as a non science background applicant. Thanks 👍
Hi Jesse, For q1, shouldn't the answer be 2? Hypothetically the second allele in a black male cat could be B, b or b* but whatever it is, in reality it can only give the ones it has. So if it was BB you would obviously just get 1 coat type offspring, but if it was Bb or Bb*, you would still only get 2 different offspring. In theory you could get 3, but in reality once crossed you would only see two difference coat types in your population depending on that second allele. Hope that makes sense and thank you for the videos !
I understand what you mean and now reading the question again, the word 'possible' is somewhat ambiguous. Since in this case, we don't know the second allele of the black male cat we must treat all of them as a possibility although in reality, it will only be one or the other not all three, since we do not know which of the three we cannot rule any of them out.
Hi, Jesse. For question 4, it asks for the probability of a FEMALE cat. Wouldn't the answer therefore be 1/2 x 1/350000. So the probability of getting a FEMALE cat with the orange allele would be 1/2 because we would not consider the males at all, would it not?
Hi Jesse, Great content as always. I'm a little confused. The stem says that a heterozygous female will always by tortoise shell. Would an orange female not then need to be OO in order to be orange?
Hey Siew, yep that’s right. Because the orange Gene is codominant the outcomes of genotypes would be OO orange female Oo tortoiseshell female oo non-orange female (this would fall back to black brown pigmentation patterns from gene 1) In males it would be a little simpler OY orange male oY non orange male (this would fall back to the outcome of gene 1 again for black and brown pigmentation) Tortoiseshell males would not be possible
@@jesseosbourne Ah, thanks. My understanding of the science was correct. I just misunderstood the information provided in the stem. Missed the bit about the mutation causing OO.
Hi there, thankyou for the amazing video! Just to confirm, for sample question 2: Is it impossible for all males offspring to have a tortoise shell colour? As in if you require Oo to have a tortoise shell and it is only linked to the X chromosome, is there any way for a male to have that colour? Or are they only ever able to be O/o x Y?
Hi Nikki, yep only the females could produce the Tortoiseshell phenotype based on this stem. It mentions that the tortoiseshell coat is a result of the co-dominance between the two alleles O and o which refers to their interaction with one another leading to the presentation of both traits = tortoiseshell. So, males would not be able to achieve this
Hi, enjoyed your video but for Qns 4 of your example, it asked for "the chance of producing an orange female cat". Therefore, wouldnt it be (1/4) + [(1/4) x (1/350000)], due to the need to consider "non-mutated" cats into the calculation?
Hey there! Almost but the trick to this question is that in the given genotypes, it is actually not possible to produce a non-mutated female orange cat as the father does not carry the orange gene meaning only the mutated version is possible to produce a female cat. Check back around 39:20 :)
Thanks again Jesse, you explain things easier than paid GAMSAT tutors I've had!
Hi Jesse! Just want to comment that as an international GAMSAT tutor myself, I found your channel to be inspirational in terms of content, format and techniques reviewed. Thanks for doing such a great job! (Regards, David.)
Hey David! Appreciate this feedback and am really glad to see that it's making a difference :)
Another amazing video! I cannot tell you how fantastic these videos have been in helping me prepare for the GAMSAT coming from a non-science background! The resources and checklist are also INCREDIBLE - you're out here doing God's work - THANK YOU!!!!
Great to hear that's helping! :)
Killing it once again with the great content, these videos are so good for revision or when stumped by a topic that i don't have time to review a textbook with. Thanks a million!
So good to hear! best of luck for this sitting!
I loved the content of the video. I found the question very hard tho and actually barely understood it. Hopefully with more revision and practise, I’ll be able to get it✨
Love your work mate. I'm sitting GAMSAT for the first time in Sep and your videos have given me a confidence boost.
Well done! I'm surprised these videos aren't more popular.
Thanks Ryan! So long as they're helping people :)
Who's here in 2024🌝?
yessir
Great review and awesome questions at the end! Appreciate you putting this together :) New to the channel and loving the content!
Amazing to hear, Jake! Thanks for watching :)
Hi Jesse! Can you explain what you mean in Q4 when you say "we don't need to multiply by half here (to account for sex ration) as the combinations of X's and Y's already cover that"?
This is brilliant, thank you, your videos are saving me!
Fantastic to hear this, Emma! Best of luck! :)
This is such a good video!!! I am new to the channel and I'm so happy to have found it. Thank you for the amazing content :)
Glad you enjoyed this one and great to have you onboard! :)
wow I really appreciate you taking the time to upload these videos, I am sitting the gamsat in March and am finding your videos so useful. Can't thank you enough!
You're very welcome, Ava! Great to see they're coming in handy :)
Hey Jesse, thanks for the content it's incredibly thorough and very much appreciated :)
Awesome, this is really great to hear! :)
Hey thank you for the videos they have been amazingly helpful for study :)
Not sure if I misunderstood Q4. It asks the chance of producing an orange female cat. Wouldn't the female cat always inherit the o from the male (as cannot inherit y) and either the O or o from the female making the probability of Oo occuring 1/2 which is then multiplied by the probability of 1/35000 to produce 1/700,000.
Hope this makes sense, please let me know if I have interpreted the question incorrectly.
Hey there, glad to hear they're helping! So if it were to be certain or known for a fact that the offspring were a female then yes, there would be only two possible outcomes of equal chance Oo (orange with mutation) or oo (non-orange)
HOWEVER
The sex of the offspring is also a probability event so although there are two possible female outcomes, there are also two possible male outcomes, making four equally likely outcomes. The sample space of this set of outcomes is shown in the diagram I draw out at 40:06
Another way of thinking about this question is satisfying a series of sequential independent events (to use some probability jargon if you're familiar).
in this case the question can be though of as "what's the probability that the cat is Female (event 1) AND it is a female carrier Oo (event 2) AND it has the mutation (event 3)?"
This would be the product of each of their probabilities
Pr(event 1) = 1/2
Pr(event 2) = 1/2 (using your method by only considering female outcomes)
Pr(event 3) = 1/350000
Pr(event 1 & event 2 & event 3) = 1/2 x 1/2 x 1/350000 = 1/1.4mil
@@jesseosbourne okay I took the cat being a female as a given but makes sense that is its own independent event. Thank you!
this series is incredibly mate, thank you
incredibly helpful *
No worries, Luke! Glad it's helping :)
@@jesseosbourne also, congrats on melbourne med!!
Very well organised detailed presentation.
I really enjoy it but I think I need to watch it again and again to get the whole scenario perfectly as a non science background applicant.
Thanks 👍
Thanks for the feedback, and glad it was helpful for you! :)
Hi Jesse, For q1, shouldn't the answer be 2? Hypothetically the second allele in a black male cat could be B, b or b* but whatever it is, in reality it can only give the ones it has. So if it was BB you would obviously just get 1 coat type offspring, but if it was Bb or Bb*, you would still only get 2 different offspring. In theory you could get 3, but in reality once crossed you would only see two difference coat types in your population depending on that second allele. Hope that makes sense and thank you for the videos !
I had the same thought..
I understand what you mean and now reading the question again, the word 'possible' is somewhat ambiguous. Since in this case, we don't know the second allele of the black male cat we must treat all of them as a possibility although in reality, it will only be one or the other not all three, since we do not know which of the three we cannot rule any of them out.
Great vid, thanks Jesse! Not sure if I'm aiming for gamsat but super helpful for uni.
If it’s helping, then I’m happy!
Awesome man - I am loving your content - thanks so much for creating it :)
Great to hear this, Edward! Happy studying :)
Thanks for this Jesse, love your content. Great question!
Thanks Brendan! Good to see it's helping :)
Hello.
Thank you so much for your videos.
Appreciated
fantastic! watching and learning
That's the goal! Thanks Maryam :)
Brilliant! Thanks.
Hi, Jesse. For question 4, it asks for the probability of a FEMALE cat. Wouldn't the answer therefore be 1/2 x 1/350000. So the probability of getting a FEMALE cat with the orange allele would be 1/2 because we would not consider the males at all, would it not?
Hi Jesse,
Great content as always.
I'm a little confused. The stem says that a heterozygous female will always by tortoise shell.
Would an orange female not then need to be OO in order to be orange?
Hey Siew, yep that’s right. Because the orange Gene is codominant the outcomes of genotypes would be
OO orange female
Oo tortoiseshell female
oo non-orange female (this would fall back to black brown pigmentation patterns from gene 1)
In males it would be a little simpler
OY orange male
oY non orange male (this would fall back to the outcome of gene 1 again for black and brown pigmentation)
Tortoiseshell males would not be possible
@@jesseosbourne Ah, thanks. My understanding of the science was correct. I just misunderstood the information provided in the stem.
Missed the bit about the mutation causing OO.
Great video as always
Appreciate it, mate!
Did you do the Sep 2021 sitting ? If yes what'd u get ?
Thanks !
Nope, just the March one this year! I'll be resitting again in March 2022
Thank you, this was very helpful!
Perfect! Really happy to hear this
Hi there, thankyou for the amazing video! Just to confirm, for sample question 2: Is it impossible for all males offspring to have a tortoise shell colour? As in if you require Oo to have a tortoise shell and it is only linked to the X chromosome, is there any way for a male to have that colour? Or are they only ever able to be O/o x Y?
Hi Nikki, yep only the females could produce the Tortoiseshell phenotype based on this stem. It mentions that the tortoiseshell coat is a result of the co-dominance between the two alleles O and o which refers to their interaction with one another leading to the presentation of both traits = tortoiseshell. So, males would not be able to achieve this
Hi, enjoyed your video but for Qns 4 of your example, it asked for "the chance of producing an orange female cat". Therefore, wouldnt it be (1/4) + [(1/4) x (1/350000)], due to the need to consider "non-mutated" cats into the calculation?
Hey there! Almost but the trick to this question is that in the given genotypes, it is actually not possible to produce a non-mutated female orange cat as the father does not carry the orange gene meaning only the mutated version is possible to produce a female cat. Check back around 39:20 :)
@@jesseosbourne Got it. thanks for the response.
This is very informative. Thank you :-)
Awesome, thanks Wayne! Glad this has been helpful :)
LEGEND
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Doggo! ❤
Do you still do private tutoring?
Sorry no I don't tutor for GAMSAT