BLAND😱? I'm pleased at least you're beginning to understand... that it's the most fascinating subject on the planet 😁 Might take a little persuading I suspect given your TH-cam name😊 Just in case you want more fascination (and you're having to do well in A level biology exams... you might find my website worth a visit www.biologycarol.co.uk 😊 This is where all my videos are - each video including exam questions at the end. This is me on a mission to try and make A level biology accessible to ALL students regardless of family income. TH-cam pays very little (A level biology is a little niche!) and this is a way that I can continue to make content that's useful to students. The website includes a way of earning money off me and there's a freebie too 'How to improve your grade up to an A*’ - so grab that at least!
I'm so glad! Feel free to check out my website www.biologycarol.co.uk for my FULL complement of videos. The WHOLE A level course has got an extra offer on til Friday 5pm - £40 for access to the whole lot for a year using the code HALFPRICE+10 at the checkout. That's less than one hour of tuition for over 50 hours of videos!! And they all include me going through exam Qs😊
Hi! I have my FULL complement of videos on my website www.biologycarol.co.uk. I've kept my favourites on TH-cam together with my Livestreams (every Tues at 5). My website is my genuine attempt to make A level biology accessible to ALL students regardless of family income AND to enable me to keep making them! Do take a look x (TH-cam earns me about £20/MONTH and each video takes over a day to make!)
Woo!Hoo! Delighted it helped! Just so you know Ive got my full selection of videos available on my website www.biologycarol.co.uk - either have a sneaky peak or watch my channel trailer th-cam.com/video/D2Qi8EW4YoU/w-d-xo.html that explains what I'm trying to do ie make A level biology accessible to all students reagrdless of family income...
Woo! Hoo! I HATE (with quite a passion😂) the diagrams that are on textbooks and revision guides! Nothings in the ‘right’ place! Really pleased you found it helpful 😊
As part of the populations and sustainability topic, the spec outlines case studies such as the Galápagos Islands. Are we expected to have a detailed understanding of these or just know the key management strategies?
Key management strategies and their effects. So 1.the human activities that occur in each place 2.the effect of each of these and 3 how these activities are controlled. Hope that helps?
Hi carol, why would you get docked a mark for talking about the nitrogen fixing bacteria in the root nodules in the first exam question? I thought that they also were involved in nitrogen fixation
Hi Abbie. Sorry for the delay 🙁. The reason why you can't talk about nitrogen-fixing bacteria in root nodules is because the question specifies 'action of microorganisms in the soil' (those last 3 words being the important bit) and that cannot include those in root nodules, only those that are free-living in the soil. Hope that helps.
Thank you Kino John! Delighted once again :) Great question - to the extent that I feel a video coming on, on this topic :) Very very briefly, you need to perfect a number of skills that are defined in the Assessment Objectives of all A level syllabuses: AO1 - recall of idea, processes and techniques AO2 - Application of this recall in theoretical practical and data scenarios and AO3 - Analyse, Evaluate, draw conclusions and refine practical procedures. In addition to these underlined skills you need to be able to do 'biology maths' and communcate your knowledge clearly using biology terminology. In essence you have to be able to learn stuff then be able to answer AO2 and AO3 questions, by practising those skills (generally by practising the appropriate Q type and learning from your lost marks) as well as being able to do the maths and communication stuff. A decent revision guide (or even my videos :)) will tell you WHAT you need to know and the terminology to use but not those AO2/AO3 skills. Higher grades requires lots of work ensuring understanding and thorough LEARNING of the content (ie EFFECTIVE revision techniques) then lots of exam question practice and then learning from the lost marks. it is worth noting the grade boundary for an OCR A* is approx 70% which means i) marks are pretty hard to get and ii) about 15-20% of the marks are not achieved by (hardly) anyone so you need to start recognising that some marks you need to 'write off' because you would NEVER get them however much you knew and perfected skills. Point ii) needs to balance your self-analysis of marks lost on marking your practice exam questions.
Thank you for the video! It's really clear and easy to understand . Just one question: with the first exam question when I first attempted it ( I paused the video ) I talked about nitrogen fixation and how free living and mutualistic bacteria turn N2 gas into nitrates, and about nitrifying bacteria. could you tell me why this is wrong and instead I should have described the action of ammonification as in the mark scheme because nitrogen fixing bacteria are also microorganisms
I'm not sure you've read the mark scheme correctly 😬... Mark points (MP) 6 & 7 were about nitrogen fixation by N fixing bacteria - which was correct. Notice you COULDN'T talk about mutualistic N fixation because the question wanted you to talk about IN the soil ie ONLY free-living N fixing bacteria. N fixation is NOT turning N2 into nitrates, its turning N2 into AMMONIUM (as per the video and my silly little diagram on the side of the Q). Nitrification was awarded in MP 3, 4 & 5, (Ammonium into nitrites then nitrates, by nitrifying bacteria). Talking about ammonification is entirely appropriate (MP 1 & 2) because the Q is asking about ALL the routes IN THE SOIL that lead to the formation of nitrates. Rotting bodies and waste (and therefore the formation of ammonium from proteins/DNA) by saprobionts are another way in which ammonium is made (in addition to N fixation) and which leads to further nitrate formation. Hope that helps x
I've JUST recorded a video about this - being inspired by your question. I will try and edit and post within a week! Hope that's ok as i think to write what you can do and why is too much for here!
Plants can ONLY absorb nitrAtes, which is why nitrification turns nitItes into nitrates. Only if the soil is in anaerobic conditions (eg waterlogged), does denitrification occur, when nitrAtes are turned into nitrogen gas. This deprives the plants of their nitrate source and makes the soil less fertile. Does that make sense? Have I sorted the confusion or added to it?! if the latter, do come back to me!
Still confused about 2 things: I thought nitrification turned ammonia into nitrates and nitrites (not nitrites into nitrates). And 2. Are you you 100% sure plants can’t assimilate nitrites? I’ve watched 2 videos where the teacher said only some plants can do so.
Jax12 Thanks for coming back to me 🙂. I'll be honest about what I am and am not sure of: 1. Nitrification DOES turn ammonia into nitrites and THEN nitrates. If you're doing OCR you need to know the bacteria involved: Nitrosomonas for NH4+ to nitrites and Nitrobacter for nitrites to nitrates. 2. I have found some references to plants absorbing nitrites but VERY few. Plants can generally absorb nitrAtes and ammonium ions (depending on the plant, and soil condition, and I guess there are a few that can absorb nitrItes in certain soil conditions). But, importantly for A level exam marks, I'm afraid you need to 'stick to the story' that nitrAtes are the ions that are absorbed by the plant (the A level 'story' is appropriate because you are being taught the simplest form of the N cycle, not the myriad of plant-specific details that are bound to exist!). So in summary, stick to Ammonium ions are converted into nitrItesn then nitrAtes by the process of nitrification. NitrAtes are then absorbed by the plant and converted into proteins, DNA etc. I hope that fully clarifies the conflicting info you have been given x
I really appreciate your help clearing a lot of confusion in my head :) If I can ask 1 last question: When it comes to symbiotic relationships between nitrogen-fixing bacteria and legumes do the legumes just use the ammonium created by nitrogen-fixation without nitrification? Do plants without mutualistic bacteria have to go through the steps of nitrogen-fixation and nitrification but plants with mutualistic bacteria (legumes) only have to do through nitrogen-fixation?
@@jax1296 Yes - the legumes (via the nitrogen fixation by mutualistic bacteria eg Rhizobium in their root nodules) use the ammonium ions directly from protein/nucleic acid synthesis. All other plants are reliant on the FREE-LIVING nitrogen fixing bacteria eg Azotobacter that live in the soil to produce ammonium ions in the soil. These ammonium ions are then nitrified into nitrite and then nitrate ions IN THE SOIL (notice the plants don't do this - as your Q implies) so that the latter can be absorbed by the plants. Hope that makes sense now!
The bottom line is that either will get you the mark in the exam 😊. What actually happens is that it is ammonia that is formed but it then combines with a H ion to form NH4+ (ammonium ion), so what ever a textbook says, its true! hope that helps x if you like my videos, do check out my website www.biologycarol.co.uk where i am attempting to provide a comprehensive collection of A level videos at a price that any student can afford (PLUS having the opportunity to earn 10% commission on friends' purchases - you could even make a profit!)
Thank you so much, I've always seen biology as a bland subject, but now, I am beginning to understand.
BLAND😱?
I'm pleased at least you're beginning to understand... that it's the most fascinating subject on the planet 😁
Might take a little persuading I suspect given your TH-cam name😊
Just in case you want more fascination (and you're having to do well in A level biology exams... you might find my website worth a visit www.biologycarol.co.uk 😊 This is where all my videos are - each video including exam questions at the end. This is me on a mission to try and make A level biology accessible to ALL students regardless of family income. TH-cam pays very little (A level biology is a little niche!) and this is a way that I can continue to make content that's useful to students. The website includes a way of earning money off me and there's a freebie too 'How to improve your grade up to an A*’ - so grab that at least!
This helped with me straighten things out. Thank you!
I'm so glad! Feel free to check out my website www.biologycarol.co.uk for my FULL complement of videos. The WHOLE A level course has got an extra offer on til Friday 5pm - £40 for access to the whole lot for a year using the code HALFPRICE+10 at the checkout. That's less than one hour of tuition for over 50 hours of videos!! And they all include me going through exam Qs😊
thank you for making all of these videos, they are so helpful.
Thank YOU! You might want to take a sneaky peak at my website www.biologycarol.co.uk where ALL my videos are...xx
I've been struggling to understand this topic, however it's no problem now. Definitely will be telling my class about you, thank you very much :)
So sorry, TH-cam has not notified me of any comments hence this very late response 😬
Thank YOU, Amelia!
Thank you for the post, I am trying to understand this as a plan for my koi pond project. I am building a bog filter with plants in it
Brilliant 😂
Speactular 👏👏
Great explanation Ma'am🙏
Thank you, Dohandra.
All the very best for your exams 👏
You are a star 👌
amazing video thanks for the help:)
Thank you so much!
You're very welcome!
FYI www.biologycarol.co.uk exists...😊
Hi Carol, I'm looking for your video on the phosphorous cycle. It says the video is Private?
Hi! I have my FULL complement of videos on my website www.biologycarol.co.uk. I've kept my favourites on TH-cam together with my Livestreams (every Tues at 5). My website is my genuine attempt to make A level biology accessible to ALL students regardless of family income AND to enable me to keep making them! Do take a look x (TH-cam earns me about £20/MONTH and each video takes over a day to make!)
This was really nice ma'am... Thanks a lot
It’s a real pleasure. Thank you for the thank you!
Thank you! What an amazing video🙏🏾
Woo!Hoo! Delighted it helped!
Just so you know
Ive got my full selection of videos available on my website www.biologycarol.co.uk - either have a sneaky peak or watch my channel trailer th-cam.com/video/D2Qi8EW4YoU/w-d-xo.html that explains what I'm trying to do ie make A level biology accessible to all students reagrdless of family income...
I wanted a detailed nitrogen cycle diagram and i got it
Woo! Hoo!
I HATE (with quite a passion😂) the diagrams that are on textbooks and revision guides! Nothings in the ‘right’ place! Really pleased you found it helpful 😊
As part of the populations and sustainability topic, the spec outlines case studies such as the Galápagos Islands. Are we expected to have a detailed understanding of these or just know the key management strategies?
Key management strategies and their effects. So 1.the human activities that occur in each place 2.the effect of each of these and 3 how these activities are controlled. Hope that helps?
Hi carol, why would you get docked a mark for talking about the nitrogen fixing bacteria in the root nodules in the first exam question? I thought that they also were involved in nitrogen fixation
Hi Abbie. Sorry for the delay 🙁. The reason why you can't talk about nitrogen-fixing bacteria in root nodules is because the question specifies 'action of microorganisms in the soil' (those last 3 words being the important bit) and that cannot include those in root nodules, only those that are free-living in the soil. Hope that helps.
Another excellent video! Thank you very much. If you don’t mind me asking, what are your tips for achieving an A* in A Level Biology (OCR A)?
Thank you Kino John! Delighted once again :) Great question - to the extent that I feel a video coming on, on this topic :) Very very briefly, you need to perfect a number of skills that are defined in the Assessment Objectives of all A level syllabuses: AO1 - recall of idea, processes and techniques AO2 - Application of this recall in theoretical practical and data scenarios and AO3 - Analyse, Evaluate, draw conclusions and refine practical procedures. In addition to these underlined skills you need to be able to do 'biology maths' and communcate your knowledge clearly using biology terminology. In essence you have to be able to learn stuff then be able to answer AO2 and AO3 questions, by practising those skills (generally by practising the appropriate Q type and learning from your lost marks) as well as being able to do the maths and communication stuff. A decent revision guide (or even my videos :)) will tell you WHAT you need to know and the terminology to use but not those AO2/AO3 skills. Higher grades requires lots of work ensuring understanding and thorough LEARNING of the content (ie EFFECTIVE revision techniques) then lots of exam question practice and then learning from the lost marks. it is worth noting the grade boundary for an OCR A* is approx 70% which means i) marks are pretty hard to get and ii) about 15-20% of the marks are not achieved by (hardly) anyone so you need to start recognising that some marks you need to 'write off' because you would NEVER get them however much you knew and perfected skills. Point ii) needs to balance your self-analysis of marks lost on marking your practice exam questions.
Thank you for the video! It's really clear and easy to understand .
Just one question: with the first exam question when I first attempted it ( I paused the video ) I talked about nitrogen fixation and how free living and mutualistic bacteria turn N2 gas into nitrates, and about nitrifying bacteria.
could you tell me why this is wrong and instead I should have described the action of ammonification as in the mark scheme because nitrogen fixing bacteria are also microorganisms
I'm not sure you've read the mark scheme correctly 😬...
Mark points (MP) 6 & 7 were about nitrogen fixation by N fixing bacteria - which was correct. Notice you COULDN'T talk about mutualistic N fixation because the question wanted you to talk about IN the soil ie ONLY free-living N fixing bacteria.
N fixation is NOT turning N2 into nitrates, its turning N2 into AMMONIUM (as per the video and my silly little diagram on the side of the Q). Nitrification was awarded in MP 3, 4 & 5, (Ammonium into nitrites then nitrates, by nitrifying bacteria).
Talking about ammonification is entirely appropriate (MP 1 & 2) because the Q is asking about ALL the routes IN THE SOIL that lead to the formation of nitrates. Rotting bodies and waste (and therefore the formation of ammonium from proteins/DNA) by saprobionts are another way in which ammonium is made (in addition to N fixation) and which leads to further nitrate formation.
Hope that helps x
So how would you go about analysing responses in terms of lost marks?
I've JUST recorded a video about this - being inspired by your question. I will try and edit and post within a week! Hope that's ok as i think to write what you can do and why is too much for here!
Oh thank you once again. Cannot wait for that video to come out!
sooo usefil, im doing gcse but this video rly helped
Fantastic. NAIL your GCSE and it will help you SO much at A level x
@@biologycarol thank uu!
Question: do plants absorb both nitrates and nitrites? Do the nitrates get absorbed by the plant and nitrites get denitrified back into atmosphere?
Plants can ONLY absorb nitrAtes, which is why nitrification turns nitItes into nitrates. Only if the soil is in anaerobic conditions (eg waterlogged), does denitrification occur, when nitrAtes are turned into nitrogen gas. This deprives the plants of their nitrate source and makes the soil less fertile. Does that make sense? Have I sorted the confusion or added to it?! if the latter, do come back to me!
Still confused about 2 things: I thought nitrification turned ammonia into nitrates and nitrites (not nitrites into nitrates). And 2. Are you you 100% sure plants can’t assimilate nitrites? I’ve watched 2 videos where the teacher said only some plants can do so.
Jax12 Thanks for coming back to me 🙂. I'll be honest about what I am and am not sure of:
1. Nitrification DOES turn ammonia into nitrites and THEN nitrates. If you're doing OCR you need to know the bacteria involved: Nitrosomonas for NH4+ to nitrites and Nitrobacter for nitrites to nitrates.
2. I have found some references to plants absorbing nitrites but VERY few. Plants can generally absorb nitrAtes and ammonium ions (depending on the plant, and soil condition, and I guess there are a few that can absorb nitrItes in certain soil conditions). But, importantly for A level exam marks, I'm afraid you need to 'stick to the story' that nitrAtes are the ions that are absorbed by the plant (the A level 'story' is appropriate because you are being taught the simplest form of the N cycle, not the myriad of plant-specific details that are bound to exist!). So in summary, stick to Ammonium ions are converted into nitrItesn then nitrAtes by the process of nitrification. NitrAtes are then absorbed by the plant and converted into proteins, DNA etc.
I hope that fully clarifies the conflicting info you have been given x
I really appreciate your help clearing a lot of confusion in my head :) If I can ask 1 last question: When it comes to symbiotic relationships between nitrogen-fixing bacteria and legumes do the legumes just use the ammonium created by nitrogen-fixation without nitrification? Do plants without mutualistic bacteria have to go through the steps of nitrogen-fixation and nitrification but plants with mutualistic bacteria (legumes) only have to do through nitrogen-fixation?
@@jax1296 Yes - the legumes (via the nitrogen fixation by mutualistic bacteria eg Rhizobium in their root nodules) use the ammonium ions directly from protein/nucleic acid synthesis. All other plants are reliant on the FREE-LIVING nitrogen fixing bacteria eg Azotobacter that live in the soil to produce ammonium ions in the soil. These ammonium ions are then nitrified into nitrite and then nitrate ions IN THE SOIL (notice the plants don't do this - as your Q implies) so that the latter can be absorbed by the plants. Hope that makes sense now!
At 2:27 you say ammonium ions but the textbook says ammonia??
The bottom line is that either will get you the mark in the exam 😊. What actually happens is that it is ammonia that is formed but it then combines with a H ion to form NH4+ (ammonium ion), so what ever a textbook says, its true! hope that helps x
if you like my videos, do check out my website www.biologycarol.co.uk where i am attempting to provide a comprehensive collection of A level videos at a price that any student can afford (PLUS having the opportunity to earn 10% commission on friends' purchases - you could even make a profit!)