Biology SL/HL help

[Mahuta ♥]

Look, if you're going to calculate a predicted grade for yourself, you're going to emotionally crushed when you get lower, trust me, do not do that. It's a very bad idea!

Papers 2 and 3 are unpredictable, the IAs are ever MORE unpredictable, you may be shocked at how much your IAs will be marked down.

I did exactly like you did last year, and trust me on this, I regret even thinking about doing it. I predicted myself a 7 after the calculations, but I ended up getting a 6 which wasn't even around in my brain!

You are going to be worried, nervous, anxious the who time till July. Enjoy your summer instead!

[Articflames]

Does anyone know any good revision sites for the neurobiology and behavior option and the further human physiology option?

If you do can you plese post the link?

[pomoni]

For the neurobiology I found those 2 extremely helpful:

http://www.sumanasinc.com/webcontent/animations/content/synapse.html

http://www.sumanasinc.com/webcontent/animations/content/actionpotential.html

If they're any help. Good luck

[almostdone!]

For Option E,

do we need to be able to DRAW diagrams (of brain, ear, eye, etc) or will they provide it and we just LABEL it?

Also, can someone explain decision-making in the CNS? Its E.4.2

THANK YOU!

p.s. test is tomorrow! eek

[Mahuta ♥]

You only need to label the diagrams, it says so in the syllabus.

I didn't do this option, so can't really answer that, but I can refer you to this:

Neurology and Behavious

[almostdone!]

Thanks :]

also, any general tips for paper 3?

also, when memorizing examples concerning organisms, is common name fine, or do we need to know scientific name (w/ genus and species)?

[sweetnsimple786]

Common name should be fine unless genus/species is particularly asked for, but it's better to say, for example, diamond rattlesnake than just snake.

[lishnaa]

Mahuta,

What is your method of studying?

Also, what do you see in biology which is really exciting?

And another question -

any hints on remembering complicated/detailed objectives?

[purplespark22]

Hello everybody!

Okay, so i've just started in the IB and to be honest, we have a crap teacher for Biology. No one gets what he is explaining and once we even caught him giving out wrong information! Anyways, the point is, i haven't learned anything from him, so i've decided to take matters into my own hands, get the Biology syllabus and just try to learn from my textbooks. It's been going okay so far, except i have one question.

I am teaching myself about Stem Cells right now, and i don't understand the difference between them and normal cells. In my books, it says stem cells have the capacity to self-renew by cell division and to differentiate. But i thought all cells had the ability to differentiate and divide! Would anybody care to explain the difference to me? It would help a lot.

Thanks in advance!

[Mahuta ♥]

Stem cells are the original cells, the very first ones that the rest of the cells differentiate from.

Stem cells can differentiate into different types of cells. Stem cells can give sex cells, muscle cells..etc..etc.

However normal cell, say, muscle cell, is only going to differentiate to give muscle cells.

When they are trying to cure cancer, they use stem cells to hope that they will differentiate to give the cells that were destroyed by the tumor.

[purplespark22]

thank you so much! Okay i have another question . It says that stem cells give human tissues considerable powers of regeneration and repair, but only some like bone marrow, skin and liver. Others like brain, kidney and heart only allow limited repair. My question is why? There are stem cells present in both, why don't they have the same ability to regenerate and repair?

[Mahuta ♥]

Well, adult stem cells are still being investigated, we do not know everything about them.

We just know they are found in organs to replace damaged cells by differentiating into the cells of the where it exists.

You do not have to know for IB Biology why this can do this and why this can't. Do not confuse yourself too much, that's med school stuff.

However I can tell you that, bone marrows have what you called the powers because it makes certain blood cells, like Red blood cells, and it does it all the time. Same for liver, which is why liver donation is much easier than any other organ, because you can cut out a piece of the liver and donate it, and that piece will give new liver cells.

All stem cells have the power to regenerate and repair, I think it's a matter of how much it does that..I am not sure really, it's something even doctors don't know yet.

P.S Nerve cells (neurones) do not regenerate at all hence: Paralysis.

I don't know why your book said brain has stem cells that regenerate..

I am merging this with the other thread.

[ILM]

Stem cells are not differentiated cells, which has many types that scientists now are research for different types of them:

i) Emboryanic stem cells which they developed very recent in human development process, they are mainly in Blastocyst, what is good in this type of stem cells that they can be differentiated on to different types of cells, and tissues. Scientist nowadays are searching for a way that they can express certain genes in the cell, so it will be differentiated for any type they want. many ethics problems raise saying that using the blastocyst mean killing the embryo.

ii) Organs stem cells: in every organ there is some stem cells that can differentiated for the cells of that organ only, they can express themseleves normaly when some cells dies. ex: stem cells in bone marrow that differentaiated foe blood cells,.

iii) Nowadays they are using stem cells from placenta and umbilical cord from an ordey borned baby, in treating many diseases espically Lukemia.(Note: You should know one of stem cells application like treating lukemia for IB).

[Mahuta ♥]

i) Emboryanic stem cells which they developed very recent in human development process, they are mainly in Blastocyst, what is good in this type of stem cells that they can be differentiated on to different types of cells, and tissues. Scientist nowadays are searching for a way that they can express certain genes in the cell, so it will be differentiated for any type they want. many ethics problems raise saying that using the blastocyst mean killing the embryo.

Yes true, but you do not need to know that for IB, I only learnt this in med school. Please do not learn information you don't need, you will have other information you need to know and understand in biology, you are still in the beginning, the chapter you're doing is like, the most simple one. That goes for you too inm.

Like you said earlier, stick to the syllabus only!

[meh]

I'm thinking of getting "Biology for the IB diploma" by Clegg and noticed that it was published in 2007. Can anyone tell me if it follows the new syllabus? I'm thinking that it must, but I just want someone to confirm so that way I don't end up spending money only to find out that it doesn't.

[Mahuta ♥]

I do not suggest getting that book.

2007 and 2009 syllabi are not that different, but the difference could be significant.

If you are going to spend money on a book, then it should be one that you could use without worrying about what has been added or removed. Otherwise, you will be obliged to keep the syllabus with you the whole time as you read through the book, checking if something in the book is still in the syllabus or the other way around. You will eventually get bored and not use the book anymore.

My best advice? get the IB Biology study guide (OXFORD) for the 2009 syllabus. That, you cannot go wrong with, and you can take my word for that. I used it all along and it has been more than useful for my revision, and it made me learn the syllabus points just as I am supposed to and more. You probably don't have the time to go through a text book anyways. (I am assuming it's a text book you're asking about)

Once again, do not get a book that is different from you syllabus.

[Sandwich]

^^ You should check which syllabus it's for. It should actually be correct -- if you think about it, the exams were sat in 2009 so the course changed starting in 2007 and the new syllabus was clearly written slightly before then. I mean, I did the new Biology syllabus and started the IB in 2007.

I doubt they'd publish a book about the old syllabus in the year the syllabus changed and became irrelevant, unless they intended to make no money out of it. So I suspect it's probably fine, I mean all my textbooks were published in '07 as well. The book that Mahuta recommended is a good one, though, so I'd consider getting that instead Or ideally getting the full version AND the study guide, as the study guide isn't the best at explaining but excellent for revision, whereas the full version is the other way around. You'll know you have the right 'full' version if it's orange with a tiger on it -- called the IB Biology Course Companion. I used both and found them extremely helpful.

[Mahuta ♥]

The study guide should have say "for 200X examination" make sure it is 2009. In that case it has been published according to the 2009 syllabus.

[dhabyahalk]

Im Stuck on a lab here!

Everyone says that i need 'literature values' to compare in my lab for my conclusion,

I cant find any in both my study guides and textbooks for chemistry and Biology

Ive already tried looking for lit. values for my experiment on google scholar, no luck there though!

is there any website where i can search for lit. values and data?

EDIT: in case anyone was wondering, the experiment was to test the 'sensitivity' of Benedict's solution on glucose, we measured the time taken for the solution to turn brown on varied concentrations of glucose.

Edited December 31, 2010 by dhabyahalk

[dessskris]

Im Stuck on a lab here!

Everyone says that i need 'literature values' to compare in my lab for my conclusion,

I cant find any in both my study guides and textbooks for chemistry and Biology

Ive already tried looking for lit. values for my experiment on google scholar, no luck there though!

is there any website where i can search for lit. values and data?

EDIT: in case anyone was wondering, the experiment was to test the 'sensitivity' of Benedict's solution on glucose, we measured the time taken for the solution to turn brown on varied concentrations of glucose.

See the quote below v

Try and get your hands on a CRC Handbook of Chemistry and Physics, it has (I feel like I'm not even exaggerating here) EVERY literature value you could ever need

Our chem teacher showed us her own copy (only the 77th edition though) and all 5 of us kind nerded over it for a good 20min, stupid bell rang and ended the fun

It was for Chem and Physics, though..but apparently Google just told me that there is CRC Handbook of Biochemistry and Molecular Biology so you may want to get it, or ask the school to get one(s) so you can just go to the library whenever you need any lit value