hi your videos have helped me so much! i was just wondering if you would at all be able to do predicted papers for the 2023 exams? im sure so many would appreciate :)
once again thank you king, I will miss watching that lovely beard educate me on the things my teachers did not, always will be in my memory, and even when I am doing Bio at uni I will be thinking of you.
As someone who doesn’t do maths at A-level, I’m super disappointed with myself on the 5 marker on the histogram as I knew that it wasn’t data for a bar chart or a scatter graph but I didn’t know how to present the data so I was completely stumped. I revised so much for that paper content wise, it really sucks that my lack of maths skills will inevitably cost me a significant portion of marks on the paper :(
T - test Error!!!!! Should have used the PAIRED t test for this example. Linking in a video from another channel here that is a really good Runthrough (the paired bit starts @7.40) ua-cam.com/video/k_OhNaQCSTc/v-deo.html
The BIOLOGY formula for standard deviation differs to that of the mathmatical one - in maths you use a different formula, which produces slightly different results. I don't know why, but your excel spreadsheet uses the maths based one. Your calculated value of 29.3 is perfect for the biology formula
Thank you for this video! For the production of beer in brewing, would all you need to know be that yeast anaerobically respires malt in grains e.g. barley into maltose via fermentation to produce CO2 and ethanol?
hi sir, i don't know if anyone else has said this, but i think excel got 28.xx because it used population standard deviation rather than the sample standard deviation you used.
after that paper 1 i’m only now realising i was allowed to criticise the scientists in evaluations😭i’ve just been blindly agreeing with them cus i assumed they’d be correct
Looking at the standard deviation question: when dividing by n the result is 28.05, but when dividing by n-1 the result is 29.3.. I think your working is correct - and so in the context of the question, 29.3 is the answer (meaning perhaps excel divides by n automatically, rather than n-1 ?)
Excel calculates population sd (28 in this case) not sample sd (29.3) if you're on the casio classwiz calculator you solve as normal on statistics (option 6) but instead of looking at sigma x look at sx (scroll down 1). Pretty sure biology papers normally ask for sample mean so 29.3 should be right!
hi mr murray, thank you so much for all your help! I was just wondering if you had an predictions on what the other 2 questions would be on as there are only 4 bullet points but 6 questions in the exam? thanks again
Those are the 4 areas given on the advanced info. I would try and prepare all the essay topics listed as who knows exactly what will come up. If you prepare all those topics well you should do ok but don’t forget to learn all module 2 content as well
Thank you so much! If you had a question where you needed to outline a method to determine if heart rate was affected by exercise would you need to record the pulse rate using the "radial artery" or could you just say use a heart monitor to measure resting heart rate?
i did so so awfully on paper 2- keep remembering every mistake i did it was so bad- i think i was just super super nervous and forgot everything😪 paper 1 was better but it wasnt the greatest and now due to my performance in paper 2 i feel like i lost any chances of getting a B in biology
Exact same situation for me . Evryone js saying paper 2 was easy, thought i was the only one who thought paper 1 was better. Im so slow i drew a bloody bar chart for the histogram question. My only chance to get a B is to get neatly full marks in unified
@@gemmabemma5554 loool you get me then. idek if paper 1 was amazing bc i made so many silly mistakes but it was better than paper 2 for sure i defo got below 40% in that paper (i drew a line graph smh so i think i was more slow than you- at least you got the block shape right). lets hope grade boundaries are stupendously low, we've got this gemma, lets redeem ourselves!!!!
@@KT-kd1yf lmaoo i prrobs messed up the mcqs too.Screw ocr and their fish. Also make sure to revise fish circulatory system in detail esp since transport in animals is on the list it most likely will be fish 🤣 Lets smash unified and hope for low grade boundaries .. And even if we dont get a B, whats not meant to be will never be... all that matters is we tried out absolute best with the time and resources we had and as much as it sucks there is always the chance to resit. We got this!
@@gemmabemma5554 haha id say the same but im resitting from last year cos exams were cancelled so i really have no choice😓 but bio usually has low grade boundaries so heres hoping
@@KT-kd1yf oh i feel bad for you, all we can do now is try our best on paper 3 and pray to god almighty for low grade boundaries (idealy same as or lower than 2021although i highly doubt it since evry1 thought paper 2 was bless
Great question. I wasn’t sure till quite recently. Paired is if it’s the same individuals in 2 situations (like the exercise example) and unpaired would be measuring if there was a difference in two totally different populations
You don’t really. On the other papers about 10-20% of marks weren’t really listed on the advanced info. I think it will probably be a little lower on this paper as no multiple choice but couldn’t say for sure
Hello Sir, I do some tutoring. Can I ask what software you use to annotate papers and record your other lessons on? Your videos are a great help to students! Thanks Francis
Nope - check the spec. It says which ones you need to memorise and which will be provided. Way down at the bottom in the maths section www.ocr.org.uk/Images/171736-specification-accredited-a-level-gce-biology-a-h420.pdf
Paired is if it’s the same individuals in 2 situations (like the exercise example) and unpaired would be measuring if there was a difference in two totally different populations
@@MrMurrayBiology okay I will go back and check! Your papers have helped me so much and I think so many other students can agree with me thank you so so much for everything you're amazing.
read through the topics, then repeat what you've read to yourself until it stays in your head. Then practise some questions related to the topic you've memorised and see which bits you don't know as good, practise them more. Its never too late to revise!
Do a mindmap with me then print another copy and try to do it all independently. Then check back to see what you missed and add that. Then do the predicted papers (independently first) and mark using the videos
![ПОЛНАЯ ИСТОРИЯ ЭКЗОРЦИЗМА [Топ Сикрет]](http://i.ytimg.com/vi/qBySr6Bt0B8/mqdefault.jpg)
THE SCHOOL HE WORKS AT NEEDS TO GIVE HIM A PAY RISE!!!!!!!!!!!
You’re actually incredible for the pace you’re producing these videos, you have helped me so much, thank you!
hi your videos have helped me so much! i was just wondering if you would at all be able to do predicted papers for the 2023 exams? im sure so many would appreciate :)
Haven’t seen this yet but gonna be the first to say this, ACTUAL LEGEND
once again thank you king, I will miss watching that lovely beard educate me on the things my teachers did not, always will be in my memory, and even when I am doing Bio at uni I will be thinking of you.
Thanks so much! Your predictions for the first two papers were so helpful!
As someone who doesn’t do maths at A-level, I’m super disappointed with myself on the 5 marker on the histogram as I knew that it wasn’t data for a bar chart or a scatter graph but I didn’t know how to present the data so I was completely stumped. I revised so much for that paper content wise, it really sucks that my lack of maths skills will inevitably cost me a significant portion of marks on the paper :(
im in the same position dw, i drew a frequency polygon🤣
Wouldn’t worry too much. If you drew a standard bar chart you’d probably only lose 1 mark for the very last bar being the wrong width
that’s what i did aswell
@@MrMurrayBiology What if I drew a line graph with a curve of best fit?
@@Alex_7899 you will get marks for title and axis I think coz it’s only meant to be a histogram other graphs won’t count
Hi Mr Murray,
Your videos have been a great help!
I was wondering if you’d be making predicted papers for 2023?
Thank you so so much for these amazing videos!!! You teach in such an engaging way and so well organised I’m so grateful you make these!!!!
I WAS THINKING ABOUT U DURING THE EXAM 😂 I was like what a legend 😂
You have single handedly saved my alevel! Thank you so so much
So helpful! Thanks so much! Excel hasn't used your sample standard deviation. The formula is for the sample standard deviation because of the n-1.
thank you so much for your predictions!!! without them i would’ve done so much worse
T - test Error!!!!! Should have used the PAIRED t test for this example. Linking in a video from another channel here that is a really good Runthrough (the paired bit starts @7.40) ua-cam.com/video/k_OhNaQCSTc/v-deo.html
Thank you so much for this!😊
The BIOLOGY formula for standard deviation differs to that of the mathmatical one - in maths you use a different formula, which produces slightly different results. I don't know why, but your excel spreadsheet uses the maths based one. Your calculated value of 29.3 is perfect for the biology formula
Thank you so much for the work you do
This man really is the GOAT
Standard deviation
σx = 28.04
sx = 29.29
We use sx in biology and the other in maths. Both are correct just slightly different ways of calculating it.
Sx is also used in ocr Mei maths
@@michelleoyewo6946 thank you for acknowledging our weird exam board
@@yasmin-pe6vn 😂
I swear its sd or at least in psych
Hi Mr Murray can you please do 2023 biology predictions your 2022 biology predictions were spot on.
Thank you so much for all your content :)
56:00 it's because Excel doesn't use (n-1. They use just (n). 9440/12 = 786.667. sqr root that and you get 28.048. Hope this helps!
thank you for everything :)
Thank you for this video! For the production of beer in brewing, would all you need to know be that yeast anaerobically respires malt in grains e.g. barley into maltose via fermentation to produce CO2 and ethanol?
Thank you so much for all the resources
35:48 For a second I thought you was gonna tell us to get into the chopper
For the HR you could also do 4/4.20 to get bps and then multiply by 60
I find it easier personally
I LOVE YOU, REAL HERO!
hi sir, i don't know if anyone else has said this, but i think excel got 28.xx because it used population standard deviation rather than the sample standard deviation you used.
Thank you sir! This probably is the last alevel biology video I watch ur right lol.
absolute legend
after that paper 1 i’m only now realising i was allowed to criticise the scientists in evaluations😭i’ve just been blindly agreeing with them cus i assumed they’d be correct
Looking at the standard deviation question: when dividing by n the result is 28.05, but when dividing by n-1 the result is 29.3.. I think your working is correct - and so in the context of the question, 29.3 is the answer (meaning perhaps excel divides by n automatically, rather than n-1 ?)
yea I got 29.35
@@k31ra77 same
Top G!!!
I love you Mr Murray
Hi, what topics do you predict might come up in the synoptic questions linking to the advanced information topics?
Thank you sir :))
Excel calculates population sd (28 in this case) not sample sd (29.3) if you're on the casio classwiz calculator you solve as normal on statistics (option 6) but instead of looking at sigma x look at sx (scroll down 1). Pretty sure biology papers normally ask for sample mean so 29.3 should be right!
Brilliant! Thanks
thank you for saving me. I may not have the best results but at least I can cry knowing I did my best
What was the fish abt??
Fish Question *
thank you so much this is super helpful
Thank you this is very helpful . will you do a video on patterns of inheritance please.
brilliant
hi mr murray, thank you so much for all your help! I was just wondering if you had an predictions on what the other 2 questions would be on as there are only 4 bullet points but 6 questions in the exam? thanks again
Those are the 4 areas given on the advanced info. I would try and prepare all the essay topics listed as who knows exactly what will come up. If you prepare all those topics well you should do ok but don’t forget to learn all module 2 content as well
Do you think maybe the Boysen-Jensen Experiments might come up as an example of a Plant Response Practical?
Yep
please can you do this for 2023 bio papers?? desperately needed!!!
Thank you so much! If you had a question where you needed to outline a method to determine if heart rate was affected by exercise would you need to record the pulse rate using the "radial artery" or could you just say use a heart monitor to measure resting heart rate?
Heart monitor would be fine! Also carotid artery is possible (the one in your neck)
@@MrMurrayBiology Thank you! 😊
YESSSS
King please do predictions for this year
You have not gone wrong. The standard deviation is indeed 29.29
for the extra q, wouldn't the cardio centre be in the medulla oblongata and not the hypothalamus? ty
Yes indeed - thought
I corrected that in the edit. Well spotted
i did so so awfully on paper 2- keep remembering every mistake i did it was so bad- i think i was just super super nervous and forgot everything😪 paper 1 was better but it wasnt the greatest and now due to my performance in paper 2 i feel like i lost any chances of getting a B in biology
Exact same situation for me . Evryone js saying paper 2 was easy, thought i was the only one who thought paper 1 was better. Im so slow i drew a bloody bar chart for the histogram question. My only chance to get a B is to get neatly full marks in unified
@@gemmabemma5554 loool you get me then. idek if paper 1 was amazing bc i made so many silly mistakes but it was better than paper 2 for sure i defo got below 40% in that paper (i drew a line graph smh so i think i was more slow than you- at least you got the block shape right). lets hope grade boundaries are stupendously low, we've got this gemma, lets redeem ourselves!!!!
@@KT-kd1yf lmaoo i prrobs messed up the mcqs too.Screw ocr and their fish. Also make sure to revise fish circulatory system in detail esp since transport in animals is on the list it most likely will be fish 🤣 Lets smash unified and hope for low grade boundaries .. And even if we dont get a B, whats not meant to be will never be... all that matters is we tried out absolute best with the time and resources we had and as much as it sucks there is always the chance to resit. We got this!
@@gemmabemma5554 haha id say the same but im resitting from last year cos exams were cancelled so i really have no choice😓 but bio usually has low grade boundaries so heres hoping
@@KT-kd1yf oh i feel bad for you, all we can do now is try our best on paper 3 and pray to god almighty for low grade boundaries (idealy same as or lower than 2021although i highly doubt it since evry1 thought paper 2 was bless
hi sir in an evaluate 6 marker on data how many data points do you need as i only tend do to 3?
Yo Mr Murray, how do you know when to used a paired or unpaired t?
Great question. I wasn’t sure till quite recently. Paired is if it’s the same individuals in 2 situations (like the exercise example) and unpaired would be measuring if there was a difference in two totally different populations
Please do predictions for the year 2024 🙏
I’m gonna miss u
Wait why at 56:54 did you put 72.9 for the standard deviation 1 if it's 14.2? Isn't 72.9 the mean?
oh nvm you noticed
how do we know that their wont be other main questions on other parts of the spec besides the advanced information?
You don’t really. On the other papers about 10-20% of marks weren’t really listed on the advanced info. I think it will probably be a little lower on this paper as no multiple choice but couldn’t say for sure
56:37 Hi sir! Is the standard deviation for 1 should be 14.2 not 72.9?
oh you figured it out later in the video. I see.
WE NEED UR HELPPP THIS YEAR PLEASE
Is everyone just revising stuff on the advance infor for paper 3 cause it's synoptic so will other topics be on there probably
@M43K how do u know?
@@akakakoook1785 its a pretty synoptic paper so other topics will definitely come up
Hello Sir,
I do some tutoring.
Can I ask what software you use to annotate papers and record your other lessons on?
Your videos are a great help to students!
Thanks
Francis
i know for his mindmap videos he uses one note so i assume it’s the same for these ones 👍🏼
And i use screenflow for video recording and editing
@@MrMurrayBiology Thats great, thank you very much!
for question 1, would I get the mark if I said "auxin inhibits lateral bud growth", not "high auxin conc..." ?
Sure - yes
1:11:00 time stamp for immune response
59:14 the answer was -8.94, are we meant to ignore the negative?
Yes - just the size of the value that counts, not the sign
Hello sir the answer was 29.3 using cassio classwiz calculator
thats what i got too
Ocr a level bio 2022 summed up = fish
What did the fish question say????
Please reply
@@shahnazraja4517 in which paper? There was fish questions in all 3 papers
Are u in yr 12 and gonna do these papers in ur yr 12 mocks
@@gemmabemma5554 no I'm scared i missed it lol
@@shahnazraja4517 oh it was the one where it had two binomial names of two fish and you had to evaluate whether they produced clones of themselves.
Could you make a video on the whole of animal transport, please? I'm totally blank on this topic.
Circulatory system is up
i really wish i did ocr biology!
Trust me you dont
If you did bad on both papers is there still chance of getting a C ???
Probs if you get nearly full marks on unified
for the t test is it not -8.94? can you have negative values for t-test
You just take the size of the value and ignore - or +
You can and yes it is negative but you ignore the sign.
do you think inheritance and variation and manipulating genomes could come up?
hopefully not
How much of a difference does there need to be for the null hypothesis to be accepted in the t test?
Value of t needs to be less than critical value. Also check my pinned comment above as I used the wrong formula 🤦🏻♂️
@@MrMurrayBiology would we need to memorise these equations?
Nope - check the spec. It says which ones you need to memorise and which will be provided. Way down at the bottom in the maths section www.ocr.org.uk/Images/171736-specification-accredited-a-level-gce-biology-a-h420.pdf
Why for the T-test do you use an unpaired method instead of a paired method?
Paired is if it’s the same individuals in 2 situations (like the exercise example) and unpaired would be measuring if there was a difference in two totally different populations
@@kadstro3392 Yeah, so why does he use unpaired in the example?
I might have used the wrong formula here. It should have been paired (you would be given the correct formula in the paper)
@@MrMurrayBiology Ah okay, thank you!
@@fd2391 about 7 minutes in has paired
you didnt go wrong i put it on the calculator
Thanks! Turns out excel calculates a subtly different version of stdev (population stdev)
How accurate was this prediction?
very accurate
Did anyone else get the same standard dev. as sir? Ive got the same answer to him but not the excell sheet :') at 56:14
It’s to do with population vs sample stdev (excel uses a different formula) also please see pinned comment at top - I used the wrong t test formula
@@MrMurrayBiology okay I will go back and check! Your papers have helped me so much and I think so many other students can agree with me thank you so so much for everything you're amazing.
What u guys write for the artery or vein question
Artery I put. Lumen looked quite small amd the walls were thick
@@jackchristian1155 same
Delete the videos, lower the grade boundaries
Do a video on how to revise😢
read through the topics, then repeat what you've read to yourself until it stays in your head. Then practise some questions related to the topic you've memorised and see which bits you don't know as good, practise them more. Its never too late to revise!
Do a mindmap with me then print another copy and try to do it all independently. Then check back to see what you missed and add that. Then do the predicted papers (independently first) and mark using the videos