as always... my procrastination got to me and now there is 24hrs until my first biology exam. Thankyou Freesciencelessons for being a countrywide backup for people like me
I must appreciate you, that you are helping out humanity. With you, humanity is learning and gaining knowledge. You clear the concepts and make subjects easy. You must have helped many people in earning A*. Thumbs up to you and your work, Sir!
Biology GCSE in a week and this guy is actually amazing, thank you so much for everything you have done for all the GCSE students, you are a hero!! Good luck with revision and for the exam guys, you'll all do great
@@seriously1680 do u know why people are so extra when they say things like "48 hours" cant they just be normal human beings and stop pretending they're like artificial intelligence and robots and just simply say "2 days"?!?!?!?
Every mock exam I see people have come here in the past for their exams. It's quite literally me now! Thank you so much Dr Donnelly, you've done so much for me, and I haven't been within 100 miles of you at any point (unlike my teachers) and now I feel confident that I can grab that grade 9.
I was so confused by this experiment because the teacher barely explained it, but your well explained but still short and precise video was a life saver
@Subhaan Bin-Naeem ye, it really wasnt good for them. it was only done because they needed a way to grade the students, but some students got grades tbey were not happy with, because they may have done worse in the mocks or on their predicted grades than the gcse. also, they may have been a naughty student, but know a lot and would have done well in the GCSE.
I’ve used your videos virtually all year and they’ve been a massive help!! I feel ready for Bio paper 1 now!! Good luck to everyone who has their exam today!!
@@urmumsfavourite well im revising for my bio mock now and its 2 hours until the exam lol- probably best to start about a month before your mocks to account for all the gcse ur taking
Before watching video Me:Just a bit of recap won't hurt AFTER UNDERSTANDING THE INVERSE-SQUARE LAW Me: That feeling when you realise your teacher skipped some major details
@@Douglas..1 yes thank you its helpful but my question is why would u even double the distance in the first place? is it because it saves time redoing the experiment or something?
If this required practical comes up, is it necessary to say the counting bubbles method or could you just describe the method with the funnel and measuring cyclinder?
Good luck in a few hours guys, even though you are scared or worried that you haven't done enough calm yourself and imagine the best possible outcome. Stressing yourself will only make you forget everything.♥️
Hi, at 3:08 why is it 4 times and not twice? I get that when you increase the distance between light and boiling tube the light intensity decreases so less oxygen is produced therefore photosynthesis happens at a slower rate but what makes you determine that it falls by four times? Thank you.
The light intensity falls by a factor of 4 causing the photosynthesis rate to drop by a factor of 4 The light intensity decreases by a factor of 4 because the distance increases the amount of area covered by the light: Like turning cm into cm^2 Your increasing the height of the light aswell as the width of the light if that makes sense.
when your measuring the volume of oxygen produced do you still use hydrogen carbonate solution in the boiling tube containing the pond weed or do you use water instead.
Hiya! I am leaving this comment to my future self for the 2025 exams. I am hoping to aim for a minimum of 8 in my triple sciences. Good luck everyone ❤
Hello, I'm a bit confused, in the practical we did at school we used water, not sodium hydrogen carbonate, when do we use each one and what would we be testing the experiment for??
You are supposed to put water with the pondweed. Only in the water you will be able to observe the bubbles and plus Sodium hydrogen carbonate is only used so that Carbon dioxide could be produced which is also a main factor in photosynthesis. If in the practical you didn't use then might* the carbondioxide wasn't produced and your practical didn't go well and if it did go well then i believe that the plant might have some carbondioxide in it already so you didnt have to use the sodium hydrogen carbonate.okay I hope you understood maybe? Huh I am really bad at explaining.
Yeah as Sadaf says, as you should know Photosynthesis has the equation: Water + Carbon Dioxide -> Glucose + Oxygen. The Sodium Hydrogen Carbonate solution supplies the pondweed with Carbon Dioxide, which allows Photosynthesis to take place more readily and removes Carbon Dioxide levels as a factor that could skew your results. Hope I cleared any doubts up.
Yes but he says in the video that you add water and not sodium hydrogen carbonate solution. It is why I am confused because surely you are supposed to add the sodium hydrogen carbonate solution and NOT water.
You add water to the measuring cylinder so that you can measure the amount of gas produced. As gas enters the cylinder, it forces out the water and leaves a pocket of the gas produced at the top of the cylinder (which you can measure) Sodium hydrogen carbonate solution is used to make the plant photosynthesise, but you don't need it in the cylinder because the plant isn't in there. The cylinder just needs some kind of liquid in it, and water is the most convenient to put in.
Anisha09 09 if it's filled with water then the oxygen produced will push the water down and then you measure how much the water has been pushed. I think the top of the funnel will help keep it upright. Hope this helps.
Wait.... instead of sodium hydrogen carbonate solution can't we just add the pond water as it is the natural environment for the pondweed? And is there a possibility that instead of moving the test tube further, the lamp could be brought nearly to the tube? Idk just simple doubts that need to be cleared... :(
You could use pond water but you would not be able to control for the concentration of carbon dioxide. You could also bring the lamp nearer to the tube.
as always... my procrastination got to me and now there is 24hrs until my first biology exam. Thankyou Freesciencelessons for being a countrywide backup for people like me
me rn 💀💀
Feel the same way right now aiming for the grade 9 victory😭🫣goodluck 🤍
This is it man, good luck tomorrow
same! the fact that you posted this five hours ago and it already has 100 likes says a lot lol
😂😂 same
exam on tuesday and binge watching free science lessons
what a bloody life saver
Same Here
haha same gd luck
All aboard the last minute revision train
how was the exam lmao
@@Ameli5a they never answer...
3 years later - exam on tuesday and binge watching free science lessons
what a bloody life saver
same
Lolllll same😅 good luck tomorrow !
It is this morning now, good luck everyone
got a bio mock literally next tuesday
@@TopMarvelRivalsPlays me too, good luck for tomorrow
Anyone here for 2024 exams?
ME
2025 😂
I must appreciate you, that you are helping out humanity. With you, humanity is learning and gaining knowledge. You clear the concepts and make subjects easy. You must have helped many people in earning A*. Thumbs up to you and your work, Sir!
69th like*
@@nimble3492 169th like
312th like
@@damndexk4127 you just messed it up
369th like
carrying on the legacy, exams in 2 days and freesciencelessons got my back
Biology GCSE in a week and this guy is actually amazing, thank you so much for everything you have done for all the GCSE students, you are a hero!! Good luck with revision and for the exam guys, you'll all do great
Good luck man my GCSEs are tomorrow too
Mines tomorrow lol love cramming
How did u do
anyone watching for biology gsce tmrw if you see this you are going to absolutely smash it
hope so :(
Let's hope so
CLAIMING W POSITIVE ENERGY 🙋♀️
appreciate it boss good luck
Thank you !!
I've got 48 hours until my exam, thank you so much, you're a real lifesaver
How did it went?
@@afrosamurai6705 bro that was ages ago he won’t reply
@@seriously1680 do u know why people are so extra when they say things like "48 hours" cant they just be normal human beings and stop pretending they're like artificial intelligence and robots and just simply say "2 days"?!?!?!?
Last minute revision squad where u at
loololol
It’s been two years
here
Late but here
@@BatSoup67 its been 2 months
Every mock exam I see people have come here in the past for their exams. It's quite literally me now! Thank you so much Dr Donnelly, you've done so much for me, and I haven't been within 100 miles of you at any point (unlike my teachers) and now I feel confident that I can grab that grade 9.
GCSE Exam on Tuesday gonna start praying now 🙏
I'm just scrolling and see all these comments from 11 months ago
revision is killing me but hopefully it's worth it
Same binging his videos the day before
@@Academicallystressedout lolll
seeing your comment from 9 months ago… amazing how time works lol. but also kinda sad
now your comment is 11 months ago and im in your exact situation
11 months ago again
Last minute revision gang
🙋♀️
😣
🥰
YEAHHHHH
started revising with 20 mins to my exam
Thanks so much for your help! If it wasn't for you I don't think I could have got 81% In my physics test! It means alot what you do;)
Thanks for the comment. I happy to be able to help.
Same
who's here for their biology exam tmr 🙋🏾♀️
me
me except way later 😘
Yeahhhhhhh!!!!! 😎
Me and it's funding horrendous
me, only 2 hours nd 40 mins left
less than 12 hours till my biology exam... binge watching free science lessons. you are a life saver
let's go everyone exam on tuesday !!
I was so confused by this experiment because the teacher barely explained it, but your well explained but still short and precise video was a life saver
Biology gcse paper 1 tomorrow and i forgot required practicals existed lmao
Update: I remembered the duckweed practical 😈
Same
lol
I got the exam tomorrow too, good luck!
How did it go
how did it go? i hope you did well
@@xcybercatzi have my gcse exam is less than 1 month just some last minute revsion
Freesciencelessons and x1.75 speed is a life saver
yeah buddy you wont be able to comprhend nor process any information beign directed towards you
this man is a life saviour
2:18 the foundation tier students got roasted ngl
Free the people in set 5
watching this the day before my exam we
jess mx same :(
me rn :( good luck!
Same
Watching this the morning before😂
good luck everyone for Tuesday and thank you so much you have been a life saver
@Tahiba Uddin me 2 wtf
my yr 10 mock is on Tuesday lol
Anybody making sure that they don’t have to suffer from exam preparation stress by revising early for the 2020 GCSEs? Or is it just me :(
did you do the exams, or not because of quarantine? hehe
this comment didn't age well lol
@Subhaan Bin-Naeem ye, it really wasnt good for them. it was only done because they needed a way to grade the students, but some students got grades tbey were not happy with, because they may have done worse in the mocks or on their predicted grades than the gcse. also, they may have been a naughty student, but know a lot and would have done well in the GCSE.
@@xhibah It kind of did. Because by the looks of it this person did well for the mocks so im pretty sure this person got the grades that was wanted.
Rip y
I’ve used your videos virtually all year and they’ve been a massive help!! I feel ready for Bio paper 1 now!! Good luck to everyone who has their exam today!!
class of 2023 where u at
MESSAGE TO YEAR 10s: START REVISING EARLIER ON DONT MAKe the same mistake as me!
Too late :/
Probably should have looked at this before revising the night before hand then?
When roughly do u recommend? Before year 11 or start at year 11
@@urmumsfavourite well im revising for my bio mock now and its 2 hours until the exam lol- probably best to start about a month before your mocks to account for all the gcse ur taking
@@justinfung4351 lmao i too late aswell
Using this to revise my practical's 1 day before the exam, thank you for being a life saver.
Before watching video
Me:Just a bit of recap won't hurt
AFTER UNDERSTANDING THE INVERSE-SQUARE LAW
Me: That feeling when you realise your teacher skipped some major details
Can you make some exam type questions and share it? That would be really helpful. You are a wonderful teacher. Also, please give key for answers.
in quarantine, gonna fail my exams, all i got now is youtube...
whats a skeleton wars
the INTERGALACTIC SKELETON WAR
Lol im sitting for the exam in *4 hours* from now!
Freesciencelessons honestly was my guardian angel
Tysm!!
ya rabb give us all amazing grades this summer and inshallah all of our fasts get accepted
ameen
ameen
Ameem
Haha anyone watching the day before the exam pahah
Nat Sodzi Yepppp! Got it in the afternoon tomorrow! Good luck x
😎
my grade is in this blokes hands
no *crys*
why of course
exam in the morning and i have been binging these videos, im so ready
Thanks this is helping so much as most of my days before the GCSE are just holidays.
So if you double the distance again (40 - 80) the number of bubbles will fall by a factor of 4 is that right?
Yes that is right
For exaple it could fall from 12 bubbles to 3 bubbles
Hope that helps
@@Douglas..1 yes thank you its helpful but my question is why would u even double the distance in the first place? is it because it saves time redoing the experiment or something?
@@layekk hes just saying that, that is the trend it usually goes by you shouldn't skip a distance
I literally have about 11 hrs until my exam and I’m still here watching this absolute ledg. I should probably be sleeping.
thankyou i have my biology exam tomorrow and your videos are a life saver
Wow, brings back the memories of revising this and that, lots of talks from friends and teachers.
When do you recommend to start revising -from a current year 10
@@urmumsfavourite whilst your in year 10
Only 1/2 hours a day. It'll help a lot in year 11
When I started revising this topic I told myself I'd aim for a grade 7. I then watched this video and told myself 'Nah I'm getting a 9.'
An hour until the exam! Last minute cramming
12 hours left until the bio exam. I love you sir xx
REVISED ALL MY PRACTICALS!
WISH ME LUCK!
A cheeky insha'allah and freesciencelessons should do it
2019 anyone?
inshallah
yeah man
Mad you were early bro revising this, you getting a 9
your practicals are perfect thank you so much! My exam is tomorrow!
Exam starts in an hour and a half come on lads
20 mins before exam 💪
night before and mornin before thank you for being my best revision resource
exam on friday and binge watching free science lessons
what a bloody life saver
Thankyou for these revision videos they do help people out and you don't fuss about and ramble, you get straight to the points, cheers
Last minute revision squad activate!!
If you are reading this, goodluck on your exams. You got this
My school is using your video in most of their lessons. Thanks for the help. 😝
Thank you for teaching us about the LED lamp! There was a question on how to improve the results, of a diagram with a 60W bulb!
Use a clear heat shield works as well
saviour for the last minute revision!
Exam is today and this man is my saviour 👏🏻
Best science teacher ever!!!!
where were u when I had no clue about science classes
If this required practical comes up, is it necessary to say the counting bubbles method or could you just describe the method with the funnel and measuring cyclinder?
They would ask if there was a better method and what it would be probably
say the bubble one because then if they ask you how to improve it, you can give the measuring cylinder version.
7 years later and still the goat 🐐
exam is today :) all the best wishes to do well in your bio paper 1 exams.
Tuesday 14 May boiiiii
rain coco can see this coming up on tuesday
You're saving my November mocks no lie
Now he needs to save me in my feb mocks
Hi ! What is the concentration of the hydrogen carbonate solution for the experiment? Thanks
You would use a relatively low concentration so around 0.1 mol/dm^3
I feel asleep watching this during class so here I am rewatching it
Hi Sir - thank you for all your work. Do we need to know how to set up a potometer, please?
how did it go
Good luck in a few hours guys, even though you are scared or worried that you haven't done enough calm yourself and imagine the best possible outcome. Stressing yourself will only make you forget everything.♥️
This came up!! Thanks mr science guy
Revision the morning of my exam, thank you so much!!
Hi, at 3:08 why is it 4 times and not twice? I get that when you increase the distance between light and boiling tube the light intensity decreases so less oxygen is produced therefore photosynthesis happens at a slower rate but what makes you determine that it falls by four times? Thank you.
because of the inverse square law
The light intensity falls by a factor of 4 causing the photosynthesis rate to drop by a factor of 4
The light intensity decreases by a factor of 4 because the distance increases the amount of area covered by the light:
Like turning cm into cm^2
Your increasing the height of the light aswell as the width of the light if that makes sense.
when your measuring the volume of oxygen produced do you still use hydrogen carbonate solution in the boiling tube containing the pond weed or do you use water instead.
Never felt better
Whos here revising 4 days before bio paper 1? --------->
12 hours 😐
the morning of 🙋🏾♀️🙋🏾♀️🙋🏾♀️
Revising a hour before my gcse 👍🏼
bio p1 tmr, thanks for the straightforward explanation.
Good ol Free Science Lessons on Biology Exam day
Hiya! I am leaving this comment to my future self for the 2025 exams. I am hoping to aim for a minimum of 8 in my triple sciences. Good luck everyone ❤
Hello, I'm a bit confused, in the practical we did at school we used water, not sodium hydrogen carbonate, when do we use each one and what would we be testing the experiment for??
You are supposed to put water with the pondweed. Only in the water you will be able to observe the bubbles and plus Sodium hydrogen carbonate is only used so that Carbon dioxide could be produced which is also a main factor in photosynthesis. If in the practical you didn't use then might* the carbondioxide wasn't produced and your practical didn't go well and if it did go well then i believe that the plant might have some carbondioxide in it already so you didnt have to use the sodium hydrogen carbonate.okay I hope you understood maybe? Huh I am really bad at explaining.
Yeah as Sadaf says, as you should know Photosynthesis has the equation: Water + Carbon Dioxide -> Glucose + Oxygen. The Sodium Hydrogen Carbonate solution supplies the pondweed with Carbon Dioxide, which allows Photosynthesis to take place more readily and removes Carbon Dioxide levels as a factor that could skew your results.
Hope I cleared any doubts up.
im going into my exam in about an hour and like, thanks dude :)
Learning this 4 hours before my exam
2:12 why water and not Sodium Hydrogen Carbonate solution
Bart Plays Games yes I need help on that fact too and also if it’s full of water won’t that effect readings please help?
it gives off carbon dioxide and therefore provides the carbon dioxide needed for the plant to actually photosynthesise
Yes but he says in the video that you add water and not sodium hydrogen carbonate solution. It is why I am confused because surely you are supposed to add the sodium hydrogen carbonate solution and NOT water.
You add water to the measuring cylinder so that you can measure the amount of gas produced. As gas enters the cylinder, it forces out the water and leaves a pocket of the gas produced at the top of the cylinder (which you can measure)
Sodium hydrogen carbonate solution is used to make the plant photosynthesise, but you don't need it in the cylinder because the plant isn't in there. The cylinder just needs some kind of liquid in it, and water is the most convenient to put in.
what 2020 quarantine be like
would increasing the distance by 3 times cause the bubbles to decrease by 6 or 9 times. is it doubled or squared is basically what im asking.
That would be 3 squared, so it would decrease by a factor of 9x
can i quit school i feel like this is way more productive i never like a teacher this much
11 hours to go and I'm still here ;)
Absolutely terrified, but thanks sir!!
its 12:24 am day of bio paper 1 and im cramming the practicals.honestly i might just do a whole night revision
2 and a half hours before the exam and I have an important question
Who would win, freesciencelessons or thanos?
Why do you fill the measuring cylinder with water? Surely it would tip out the way it is positioned in the diagram?
Anisha09 09 if it's filled with water then the oxygen produced will push the water down and then you measure how much the water has been pushed. I think the top of the funnel will help keep it upright. Hope this helps.
We put our boiling tube inside a conical flask instead of using the cup of water between. Of course, we filled the conical flask with cool water
brilliant last minute revision for tomorrow! Thanks for saving my bacon.
Wait.... instead of sodium hydrogen carbonate solution can't we just add the pond water as it is the natural environment for the pondweed? And is there a possibility that instead of moving the test tube further, the lamp could be brought nearly to the tube?
Idk just simple doubts that need to be cleared... :(
You could use pond water but you would not be able to control for the concentration of carbon dioxide. You could also bring the lamp nearer to the tube.
@@Freesciencelessons Ah alright, I get it... Thanks for ur help!
good luck tomorrow :D
do we start a stopwatch as soon as first bubble is produced ?
No just start stopwatch and then count no of bubbles
no just when your ready as the plant had time to acclimatise
Also, please make a video on System Nervous Co-ordination. :)
my fav science guy
Which practical should we write about in a 6 mark question, bubbles or volume of oxygen?!
I'd say the volume one as it is more accurate but they probably would allow the bubbles one
Any