Biology SL/HL help

[photorazzi223]

um....i have this question. how can you calculate the cell of the size. i mean i have field of view and no. of cells in the diameter but i dont have the magnification... aaaa freaking out!

I am doing this onion lab report where i need to find size, number and age for layer of the onion and right now i am at CE. i have this questions ... um.... why are there more cells in the inner layer than the outer layer of the onions? I know that inner layers are the youngest but why....? Can anyone help me with that?

I am doing this onion lab report where i need to find size, number and age for layer of the onion and right now i am at CE. i have this questions ... um.... why are there more cells in the inner layer than the outer layer of the onions? I know that inner layers are the youngest but why....? Can anyone help me with that?

[HappyCamper]

Hey there!

I Have a question pertaining to my Biology Heart Rate IA.

We have to do carry out a plan and design investigating a name factor that affects the heart rate and I want to do caffeine. However, I know that IB has rules pertaining to the use of humans and having their written permission in order to carry out your tests.

Therefore, do you think I can go ahead with my experiment manipulating the amount of caffeine given to a student without getting their signature, or is it absolutely necessary?

Thanks in advance!

[kim luffy]

Hey there

We did the same experiment actually. Does it necessarily have to be caffeine? You could do it on something else like music. My group and I did it on how different genres of music affects the heart rate of a person, including the volume at which the song is played at. It will be much easier than caffeine cause you don't need any consent.

However, if you want to continue with your own idea, yes, i think you should get consent. That way, you can write it down in your experiment and state you got consent with probably a piece of evidence. But i would ask your teacher about this really. They would have a better answer.

Hope i helped and good luck with it

[SurajM]

do you have any revision for option H? Further human health and physiology?

I really need revision notes on option H and human physiology 2 (HL)

Help!

[Coping.with.IB]

Hi Mahuta,

I am doing an extended essay in Biology. I chose the topic of breast cancer. I have the statistical representation and stuff of my homeland but I don't know what my research question should be. The teacher says it has to be very specific and stuff. Mind helping me? Thanks

[Emmi]

Hi Mahuta,

I am doing an extended essay in Biology. I chose the topic of breast cancer. I have the statistical representation and stuff of my homeland but I don't know what my research question should be. The teacher says it has to be very specific and stuff. Mind helping me? Thanks

Unfortunately we cannot come up with a question for your EE, it's something you're graded on and to come up with a topic for you would be cheating. In order to do well in a biology EE, you'll want to do some sort of experiment, as data-based EEs rarely do well (if ever). I'm not so sure your current topic of breast cancer would really do well at all. How would you test this? You might have to come up with a new topic. Your teacher is right that it needs to be very specific, but it doesn't have to be so focused you hit 2000 words and get stuck. Science EEs can have a lower word count, but this is made up for with equations, data, and other working. So I'd suggest coming up with something else, something you can experiment with.

[Mahuta ♥]

As probably mentioned above, an EE in biology MUST be experimental. I can't think of anything regarding breast cancer that can be experimented in school labs. It's going to be very difficult to write an experimental EE on breast cancer, why? Well so many reasons one of which is that you have to always make sure that you're not deviating to the medical side more than the biological side..because remember..this is a BIOLOGY essay not a medical one, and obviously..with breast cancer, it's going to be awfully difficult to focus on the biological side more than the medical side.

Unless you can come up with a way to link biology (as an experimental science) to breast cancer, I strongly urge you to change your topic.

[Rainstarnc]

I am in such big trouble, because I procrastinated way too much and I don't understand what I'm working with.

I've been assigned to do my HL Bio IA on the effect of substrate concentration on lipase. I've been trying to begin but I hardly know what I'm working with. The design phase of my IA is due tomorrow, and I only have a few steps of procedure so far. Everywhere I look online, they talk about how to measure it with temperature of pH balance but I need it to be specifically concentration of substrates; it's too late to change it to anything else now. I have to use milk as well, not butter or anything else (I read another forum where a different student had this same problem but you all convinced him to switch to amalayse (spelling ) before my questions could be answered). I also know I need a pH buffer but I'm not sure what that means, nor where to place it in my procedure. Or do I really need a pH buffer? I know the pH should be about 8, and that the temperature should be about 98 degrees fahrenheit. I also don't know what my dependent and independent variable would be.

Would it work if I had the same amount of milk (plus bile salts to emulsify the milk fats, because from what I understand that's necessary), but a different amount of lipase each time? Or maybe the other way around?

Edited September 22, 2013 by Rainstarnc

[kristen.nader]

Hi

I just started IB well not just started....we have covered chapter 6 evolution and parts of chapter 1 cells.

Is there any eay that you would be so amazingly kind as to send notes on these chapters?

My teachers is really strict and even though I love biology I'm really worried.

please help<3

[Alicia Maldonado]

Hi, I'm having problems with memorizing stuff like the phyla of plants. Actually, I see topic 5 as extremelly boring haha I prefer a LOT more the topics about physiology and idk everything that has to do with humans. Mahuta, do you have any mnemotechnique to learn the difficult memorizing parts of topic 5? Moreover, there is an objective at Option E.2 about the visual stimuli the one about the Edge enhancement. Not even my teacher knows how to explain it. Can you give me a response to that objective the way it should be written in a 6-marker on paper 3? Thanks a lot! I also want to study medicine next year here at Peru

[kanata_zero]

About the edge enhancement, I doubt there'll be a 6 marker question based on that. I've never seen something like that in the last 10 years papers. Edge enhancement is a phenomenon that can be best demonstrated by the Hermann grid where grey blobs are appearing in white lines. This is a product due to the structure of the receptive field of your eyes. The receptive field is a circular patch that has a centre which mainly has ganglion cells that stimulate neural activities and the surrounding area has ganglion cells that inhibit neural activities.This is how I would answer since it's what it says in my textbook.

Here's the explanation. As a result, when you focus your eyes on the black portion, the black portion will be on the centre while the white areas will be on the inhibitory area, so your brain will definitely know that's black but the optic nerve aren't giving enough information about the white areas so grey blobs are being formed cuz there's so much focus on the black areas. When you focus on the white areas, the black areas surrounding it will look whiter because there's more focus. Hope it makes sense.

About the plant phylums, just keep memorizing. It's frustrating but you'll get used to it

[rose04]

I'm doing this project in SL Biology. The independent variable in the experiment is measuring air pressure. However, I don't have a baromoeter or anything like that. So I was wondering, do you know any other ways to measure the air pressure in a ziplock bag? I really hope you can help me or at least help to lead me on the right track if possible. Any help would be greatly appreciated!!

Edited January 5, 2014 by rose04

[sprout_1147]

Hello Mahuta

I am working on my biology IA, design lab, on the innate behaviour in invertebrates (taxis or kinesis) (Topic E3).

I decided to investigate the chemotaxis of ants to NaCl. I explained why ants in general need NaCl (salt) to maintain life.

After handing in my draft, my teacher told me that I have to look up on the internet the NaCl concentration favored by the particular species of ants that I chose, rather than ants in general.

Is this required? I mean, were your bio teacher as picky as mine?

[Mahuta ♥]

Your teacher is just being careful, IB Moderators could pick on anything that sounds vague or unspecific. Also, I think that's kind of significant. I have no idea what sort of NaCl concentrations certain ants need..but I think it could go from nearly 0 to a very high concentration, so it's the kind of thing you do need to put down to justify the concentration of NaCl you're using when writing the 'Design' part of the IA.

[Ayumi]

Hi Mahuta,

I was wondering if you have any tips for answering the data analysis questions? I always have problems with those and that's where I lose all my marks

Thanks

[Sandwich]

https://www.facebook.com/IBSurvivalFreeRevision/posts/601987513176447?stream_ref=10

^^ The tips on there might help you, Ayumi.

[IBdoingthistosurvive]

IF ANYONE NEEDS HELP WITH DESIGN LABS - DON'T HESITATE TO MESSAGE ME! My top 2 are 5/6 and 6/6 and my first was a 2/6 so trust me, I know the difficulty to bring your partial/incomplete to a complete x) So happy to aid

I can also help with DCPs - but I noticed that the forums about them are very informative, so check them out before messaging please!

[IBdoingthistosurvive]

Hi Mahuta,

I was wondering if you have any tips for answering the data analysis questions? I always have problems with those and that's where I lose all my marks

Thanks

I'm also struggling with them, but I'm improving by just googling past exams, and doing all the database questions related to the unit There truly is no other solid solution..it's true practice helps x)

[IBdoingthistosurvive]

Hi

I just started IB well not just started....we have covered chapter 6 evolution and parts of chapter 1 cells.

Is there any eay that you would be so amazingly kind as to send notes on these chapters?

My teachers is really strict and even though I love biology I'm really worried.

please help<3

I use these websites for notes, other than the textbooks (if your teacher gave you textbooks, USE THEM, they're honestly your best friends):

ibguides.com

http://www.ib.bioninja.com.au/ib-home/

http://click4biology.info/

Hope this helped~

[ibfederer]

Hey guys,

My teacher is new to the IB and does not know the process too much. For Biology HL, how many labs do you send in to the IB? And for the PSOW, I know you list all the labs but is there a specific way? Do you have to send lab reports for each lab you listed? And what if you're total hours doesn't equal 60?

Thanks a lot!