Biology SL/HL help

[Drake Glau]

I could see it being possible just because of the size of the peas. Wouldn't take much to cut the weight in half. Go test it

[Mahuta ♥]

I tried to find the amount of water in a pea seed, but I couldn't.

The best way to get an exact answer is to have an estimate of the amount of water in a pea seed.

However if I try to make an educated guess..seeing a turgid one and a dry one, the difference shouldn't cause the mass to drop down to half. That's what I think anyways, especially if you try to squeeze the dry one you'll see that it's actually almost full inside. That being said, I looked up a dry pea seed, not sure if they showed a completely dried seed, if they didn't then probably yes it would go down to half. I am not sure though..

So if I were to answer that question in an exam or something, I would say no, it's too harsh, unless I have values.

[Serene Z]

Study tips for IB Biology, anyone? Really stuck... I have no strategy at all.

[Mahuta ♥]

Here's a good topic about this:

How to do well in biology

This should be good if you a may2012 candidate..If you're may2011, some may not be as efficient. So go take a look, if there's anything you're unsure of ask.

[Serene Z]

I'm terrible at taking Bio notes... haha. I often don't even know what I even wrote during the lesson, when I refer back to them. They're really cluttered, but I find that if I try to arrange them nicely, then I miss out on some important bits.

BTW, do you think that there should be a different study method for each topic? I'm doing SL Bio.

I'm not good with high-memory subjects in general. It would help if I really like Biology, but sometimes i feel quite bogged down by all the information.

Did you study Bio just by taking notes? Were there any topics you didn't like? If so, how did you deal with it?

[Mahuta ♥]

I'm terrible at taking Bio notes... haha. I often don't even know what I even wrote during the lesson, when I refer back to them. They're really cluttered, but I find that if I try to arrange them nicely, then I miss out on some important bits.

BTW, do you think that there should be a different study method for each topic? I'm doing SL Bio.

I'm not good with high-memory subjects in general. It would help if I really like Biology, but sometimes i feel quite bogged down by all the information.

Did you study Bio just by taking notes? Were there any topics you didn't like? If so, how did you deal with it?

I personally can't work without my notes, even now in my medical studies no matter how much work I have to do, I will still work with my notes. Back in school, I was able to make good notes that I didn't have to re-write again and organize. However if your class notes are not too good and cluttered, re-write them when you get back home. It's SL, so it shouldn't be too much. I totally understand that having cluttered notes just makes everything seem messed up and hard to know..etc..etc.

Another way of being on top of things in bio, is having the Oxford study guide (Allot) and taking it with you to class. This book follows the syllabus and the information is very organized so that 1 or 2 syllabus points are put in a box. I am suggesting this, because you have to have a way, no notes (good ones) and no books..you'll be lost.

Some people feel that some topics need different methods than others. With me, biology was either: 'Understand&Memorize' parts or 'Understand', I use the same method for all, because they both need me to understand and I understand using my notes and the study guide, the syllabus sometimes as well. I usually work with bullet points in my notes, makes them easier to read than if they were like..paragraphs. I think why I use notes a lot is that the notes are written in my own words, so it's not like me copying what's written on the board or something. The teacher talks...I understand what he just said and I write it down.

My biology teacher taught me for 4 years and he was great, the one that taught us IB2 was really good too, so that helped a lot. However if your teacher isn't good, doesn't mean you can't do good. I always tell the people here if you have a bad biology teacher, you have your syllabus, notes and/or study guide and the internet. Even with my teachers I always kept the syllabus in front of me during the lesson, making sure I understand a point in the syllabus before they moved to the next one.

Yeah having all that information does make you less and less keen to work on it. Main reason is that you left it for so long that now, looking at it it's just a bunch of notes you have to read and understand. Choose a weekend and make it for biology, organize your notes and re-write the ones that are too 'all over the paper'. When you're done with that, get a copy of the syllabus (we have it on here), and go point by point and just put a tick next to points you guys finished in school. Knowing how far you are in the syllabus prevents you from feeling completely lost in the subject. On the points that you finished in class see the ones that you are completely lost on and check a text book if you have or post in this topic, we will clarify things for you.

I loved most of the biology topics. I didn't hate any..I just didn't like some. For example, plant science. I just didn't find it interesting at all. I knew that if I am going to keep avoiding it, it will be a disaster when it comes to exams, so I just worked on the notes and tried to understand it and just...got it out of my way. I still remember everything in my Bio HL except plant science! I just didn't like it. But avoiding things you dont like..but have to learn is a disaster trust me.

You just a need one weekend to organize biology in your head and reading it and liking it will be much easier.

Hope this helps.

[dessskris]

I'm terrible at taking Bio notes... haha. I often don't even know what I even wrote during the lesson, when I refer back to them. They're really cluttered, but I find that if I try to arrange them nicely, then I miss out on some important bits.

BTW, do you think that there should be a different study method for each topic? I'm doing SL Bio.

I'm not good with high-memory subjects in general. It would help if I really like Biology, but sometimes i feel quite bogged down by all the information.

Did you study Bio just by taking notes? Were there any topics you didn't like? If so, how did you deal with it?

Awww I feel bad for you I know how you feel, I used to take Bio too (until year 10) and I really sucked at it thank God I'm not taking IB Bio

Anyways... I would say that Bio is not about 100% memorising. Another important aspect is, as Mahuta pointed out, your understanding.

You need to understand every single concept. If you can't, just memorise but since you are not good at high memory subjects (me too! high five! that is why I kind of failed my Bio (esp in years 8 and 9 )) memorising is not an easy job. So, what can you do then?

Listen to your teacher during lessons! How does your teacher teach? Do they give you handouts or read through the textbook? When they are explaining something, take note of every important thing that they say. Write it on the handouts or use post-it if your teacher reads through your textbook. This ensures that you won't lose your notes because they are written in the handouts (unless you lose the handouts ) or in the textbook and are written next to things that are related to that so you are unlikely to wonder which topic is this note on. Highlight the important things in your handouts&textbook. You should listen to them and ask if you don't understand something. When I said take note of every important thing that your teacher says, you may have a different definition of an 'important' thing, so I suggest writing down everything that your teacher mentions that is not found in the textbook nor handouts nor study guide, because you don't know if you will need that in the future it might be something important sometimes.

Write your notes in bullet points. Include diagrams where necessary and do not doodle on your notes

I don't think different study methods for different topics is necessary study with the method that works best for you.

I studied Bio by listening to my teacher and reading the textbook&handouts. TBH I didn't do well in my IGCSE Bio because my teacher never taught well and I didn't quite like her so I never really took up any lesson from her explanation haha but a few weeks ago a friend doing IGCSE Bio came to me and asked me to help with her HW, idk how to do those questions but it turned out that the answers could be found if I read the textbook and I finally understood it. So my point is that reading your textbook is worth it

Haha I didn't like any of the Biology topics but I still tried to do my best and accept the truth that I must study those you need to get a motivation good luck thejollydude!!

[jchiangg]

hey mahuta, i've got a lab to do on fruit flies.

i get to pick one allele to manipulate and make them breed and whatnot with this program that i've downloaded. my teacher tells me to design the lab and everything myself, but i have no idea what kind of aim to give myself other than - "Discover whether if the chosen allele is recessive, dominant, or co-dominant." I don't think that's a very suitable aim and so if you can, do you mind pointing me in the right direction?

(:

Edited February 20, 2011 by jchiangg

[just do it]

hey, I'm in bbiology class, and i'm makink a lab about woodlice. i already have the enviromental factor that affects its distrubution and, the data of the control grou. Now i need to know whta processes can i do, graph, standar deviation, i don't know.

thanks a lot

[kiwi.at.heart]

hey, I'm in bbiology class, and i'm makink a lab about woodlice. i already have the enviromental factor that affects its distrubution and, the data of the control grou. Now i need to know whta processes can i do, graph, standar deviation, i don't know.

thanks a lot

So what is your data you have collected like? how many variations of you independent variable did you have? A bit more information about your results would make it easier to give you advice.

[Hinuku]

Hello,

I need help on three things, I just don't know what I should know about them, here they are:

1. Electrophoresis
   
2. restriction enzymes
   
3. Polymerase chain reaction
   

The main problem is that there is no information about these topics in any of my bio books and I really need the knowledge for tomorow!! ;p

Thank you

Matthew

[Mahuta ♥]

Okay no problem:

*4.4 Genetic engineering and biotechnology*

1)Electrophoresis:

It's mentioned 2 times in the syllabus where it says:

"State that, in gel electrophoresis,fragments of DNA move in an electricfield and are separated according to their size."

and

State that gel electrophoresis of DNA is used in DNA profiling.

So basically electrophoresis is the process through which we separate molecules of Nucleic acids or proteins according to size and charge. In the biology syllabus you're asked to know about the DNA electrophoresis. We take a sample of a DNA and put different fragments of it on a gel sort of cube that is charged..one side negative and the other one positive. When the charge is applied, these samples will move according to their size which will allow us to observe the different fragments since the heaviest will travel less. This technique is used in DNA profiling, which is basically the genetic fingerprinting. It's used for paternity tests by taking a sample of the child and the 'man' and they observe the two 'ladders' they get to see the similarities.

Okay, so that was for you to understand it. All you need for the exam is to state what is mentioned above. You usually get MCQ on these things.

Here's the apparatus:

And here's the result you get:

2)PCR: Polymerase Chain Reaction:

The syllabus says:

"Outline the use of polymerase chain reaction (PCR) to copy and amplify minute quantities of DNA."

When you're testing DNA, it's usually difficult to get a sufficient amount that allows you to have several trials, which is why they use PCR. It's a reaction that gives you multiples copies of the DNA you are testing in order to provide the sufficient amount. PCR is used to amplify the DNA used in electrophoresis.

It says outline, so basically that's all you have to know. You do not have to know the details of the method as the syllabus clearly states that you don't.

3)Restriction enzymes:

It comes within the process of genetic engineering, and the part of the syllabus that mentions these enzymes require you to know an outline of the process:

Outline a basic technique used for gene transfer involving plasmids, a host cell (bacterium, yeast or other cell), restriction enzymes (endonucleases) and DNA ligase.

I already explained this a few pages back, here it is again:

This is basically the new technology of taking certain bits of DNA of an organism and putting it into the gene of another.

Main example you have to know:

Genetic modification that is used in the production of human insulin.

1. mRNA coding for insulin is taken from the pacreatic cells that produce it.
   
2. Reverse transcriptase is used to make DNA from this mRNA.
   
3. 'G' nucelotides are added to each end to allow it to stick.
   
4. Now the insulin gene is read.
   
5. A plasmid (small hoop of DNA in bacteria) is extracted from the bacteria and opened using restricting enzymes
   
6. C nucleotides are added to each side of the plasmid(to stick to the 'G' added on to insluin gene).
   
7. The insulin gene and the plasmid are stuck together, however, they leave nicks in between.
   
8. DNA ligase(also used in replication) heals these nicks by adding sugar-phosphate bond.
   
9. The plasmid witht the insulin gene is called 'recombinant'. It is inserted into the bacteria.
   
10. The bacteria/host cell normally used is the E.Coili bacteria and it starts producing human insulin.
    

Hope this helps.

[Papi]

This is a novice question, but our teacher never really explained Photosystem I and Photosystem II properly, like what they are where they are etc... And he barely explained Photophosyphorylation, think you can help?

Edited March 13, 2011 by Papi

[Drake Glau]

photophosphorylation is phosphorylation but uses light energy for it's source of energy

First thing to remember about those two are that photosystem II actually comes first and both are the process of exciting electrons using the energy from light. I don't remember the details which is what you're looking for I'm sure (been too long, need to review this apparently =/), sorry =/

[Mahuta ♥]

Alrighty.

Thylakoids are organelles/compartments found inside the chloroplast as you know. Thylakoids are membrane bound, in other words they have a lumen(containing everything needed for the light independent reaction) that is surrounded by the membrane( containing the proteins of the chain). Try to think of them as a discs:

When they're stacked together they become connected with each other, forming a granum and with other stacks(grana). Here's a picture of 3 thylakoids connected:

Like I said previously, the membrane contains the proteins forming the electron transport chain. Within this chain there are 2 'units', each containing hundreds of the green chlorophyll molecules (the main photosynthesis pigment). They are the units that capture the light and they're called photosystem. For SL, that's the maximum you have to know about photosystems.

As for the P1 and P2: they are found within the chain, basically 2 different types of units.

All you have to know is that light is captured by the P2 first then P1.

[IBavictim]

Hi, I'm amazed at how you remember and explain things so well!

See right now I'm having trouble remembering Cellular respiration [Topic 8--or more specifically 8.1.4(Explain aerobic resp., link reaction, krebs, role of NADH + H+ , Electron transport chain, role of oxygen) and 8.1.5(explain oxidative phosphorylation in terms of chemiosmosis) ].

When I read over my notes, everything would be familiar to me (I'd look at it and I'll be able to say 'yeah I get that' 'yes, this is how it happens and it's because of this factor' ). However my problem is that if I am given this specific question to answer, I actually wouldn't be able to answer all that well unless it's a Paper 1 Question! -It sounds strange, I know D= —I can't even begin to explain my troubles with plant science! I'm not too enthusiastic about...plants

How do you remember all the processes, products, roles, significance, etc. ?

Thank you in advance!

[Mahuta ♥]

Hi, I'm amazed at how you remember and explain things so well!

See right now I'm having trouble remembering Cellular respiration [Topic 8--or more specifically 8.1.4(Explain aerobic resp., link reaction, krebs, role of NADH + H+ , Electron transport chain, role of oxygen) and 8.1.5(explain oxidative phosphorylation in terms of chemiosmosis) ].

When I read over my notes, everything would be familiar to me (I'd look at it and I'll be able to say 'yeah I get that' 'yes, this is how it happens and it's because of this factor' ). However my problem is that if I am given this specific question to answer, I actually wouldn't be able to answer all that well unless it's a Paper 1 Question! -It sounds strange, I know D= —

How do you remember all the processes, products, roles, significance, etc. ?

Thank you in advance!

Thanks, haha I am glad to help. I still remember all this because I loved it so much and I have to keep it all in for uni.

Yes I totally understand that problem, I used to have that with some of the chemistry topics.

Anyways, for cell respiration, I followed the syllabus but in a slightly different way. For example,it mentions krebs cycle, role of NADH+H+, ETC and role of oxygen all in one point. My teacher split it to:

1)Link reaction

2)Krebs cycle

3)Oxidative phosphorylation (come with the ETC).

The role of NADH + H⁺ and oxygen was mentioned with the points above.

Now the thing is, yes you will be reading and saying "yes..that makes sense".."yes I understand that", but trust me if you really understood it, you would be able to explain it to yourself from scratch. This is how I did it, so I read it and understood it, I would then have a white paper in front of me a pen and try to explain it to myself. There's nothing that could make something stick in your head like explaining it to someone(or you).

So the first thing you have to do is make sure you really understand that. To make sure of that, are your notes clear and summarized with clear diagrams? Did you deduce 'hints' of each step (e.g Krebs cycle) that will help you remember it? That's what you could try doing, it makes things like the krebs cycle really easy, here's how:

Krebs cycle is basically:

2C+4C=6C---->5C------>4C'------->4C yeah?

Here are the 'hints' I kept in mind:

• Every time a C is lost, CO₂ is lost.
  
• Every time CO₂ is lost, H₂ is lost as well.
  
• Every time H2 is lost, it is taken by the NAD⁺ making NADH+H⁺.
  Exception:: For the 4C'----->4C : We want to get back the 4C we started with, we have to remove 2H₂, one is taken by NAD+ and the other by FAD.
  

So basically in the exam just make the diagram above, and for each step an arrow out for CO2 and another one out for NAD+ becoming NADH+H⁺. For the last step just replace the arrow out for CO₂ with FAD becoming FADH₂.

Not sure this is clear, but you get my point. Try doing that for each step, it will make things much easier.

Remembering Significances and roles just comes with the process itself, I mean if you know the process very well..you would know the roles of each thing and their significances. As for the products, you could either make a list of the products and let that list be a guide for you when you're trying to remember the process and steps..etc, or understand the process very well in which case you could just deduce the products. I mostly went with the latter, just made more sense. I used the fist way for things I just couldn't understand very well (eg. some of the things in chemistry)

If you want my explanation:

Kreb's Cycle

Glycolysis --to--> Oxidative phosphorylation.

Let me know if something is unclear or you need it to be explained.

I can't even begin to explain my troubles with plant science! I'm not too enthusiastic about...plants

Haha Plant Science was my least favorite topic, but I still used a similar method to remembering things. To be honest, Plant Science wasn't hard, it was just..not interesting..at all.

Is there something specific in that topic you find difficult?

[IBavictim]

I went through Plant Science and photosynthesis last night and it wasn't too bad

The ones that I find harder to understand/remember are :

-Explaining light-dependent and light-independent reactions

-C.4.4 Explain photophosphorylation in terms of chemiosmosis.

Also, do you happen to know a great resource for the Options part of the syllabus? My teacher said we only need to learn E-H

Thank you for taking your time to help!

P.S. Thanks for the studying tips—They did actually help me !

Edited March 25, 2011 by IBavictim

[Sandwich]

Also, do you happen to know a great resource for the Options part of the syllabus? My teacher said we only need to learn E-H

For HL IB Biology you actually only need to know 2 options, of your choice So E-H is a bit of overkill!

Best resource (IMO) is the syllabus + a good IB textbook e.g. the Allot & Allot Course Companion for Biology.

[IBavictim]

Also, do you happen to know a great resource for the Options part of the syllabus? My teacher said we only need to learn E-H

For HL IB Biology you actually only need to know 2 options, of your choice So E-H is a bit of overkill!

Best resource (IMO) is the syllabus + a good IB textbook e.g. the Allot & Allot Course Companion for Biology.

2. . .options..?

You see, I was never told that ! O.O

I have been trying to drill them in my head and I could only remember E AND H!

(I can't believe I'm so happy about a tiny thing!!)