Don't miss

How Height of Leaves on Holly Bush Affect Prickliness - Biology IAA


Within this post will be all you need to know for this IAA experiment. Once again, this experiment is boring and simple which means there must be no slip up in the method at all.


Firstly, we got to know what the independent variable and dependant variable is:


Independent variable - height of the holly bush
Dependant variable - length of leaves and prickliness


Independent variable) causes a change in (Dependent Variable) and it isn't possible that (Dependent Variable) could cause a change in (Independent Variable). So, the height of the holly bush causes a change in the the length of leaves and prickliness.


Remember when setting out the graph, the independent variable ALWAYS goes on the 'x' axis while dependant ALWAYS goes on the 'y' axis. So for this case, the height of the holly bush would be on the 'x' axis and the length of leaves or average prickliness (I done average prickliness) is on the 'y' axis, because that is the variable you are not changing.

How to measure prickliness
Number of pricks X height of tallest prick
So, if a leaf had 10 spines/pricks and the longest spine/prick was 1cm, to work out prickliness, you would do 10 X 1 which would give a prickliness of 10 for that leaf.

Method
1) Identify a holly bush.
2) Using you hands, remove 10 leaves that are around the same length, size and colour at ground level from the outer bush.
3) Repeat step 2) but one meter up using a meter ruler to measure this, then two meters up.
4) Separate leaves into groups to help prevent leaves from being categorized wrong.
5) Using a 30cm ruler, measure leaves length ways to 1 decimal place and record results.
6) Measure the size of the longest prick on each leaf to 1 decimal place. Count the number of pricks on the leaf and times that number by the longest prick number. Record results.
7) Repeat steps 1-6 three times using different selection of leaves from the same holly bush at the same height.
8) Repeat steps 1-6 three times using 3 different holly bushes, all the same species found in the same area and time.
9) Ignore any anomalous data and repeat experiment to compensate for this.

Your graph should look something similar to this:




The method was made valid by (The point/Explanation for the point)
Using the same 30cm ruler and meter ruler so results are recorded accurately
Use same person measuring as eye sight may differ affecting results
Same species of holly bush as different species will have different lengths of leaves and pricks
Location of the holly bush so that the three holy bushes we tested weren't different in any way due to the environment
When we measure sample as leaf and prick size may differ in different seasons 
Time of day we picked the leaves so the leaves are at the same growth.


The method was made reliable by
Measuring length of leaves and longest prick to one decimal place
Repeating the experiment
Ignoring any anomalous results and repeating to compensate
Measuring 10 leaves instead of 1
Way in which we removed the leaves
Placing leaves into groups to stop confusion

Conclusion
(this is where you should use your results and scientific knowledge)
As the leaves were collected further up the holly bush, the prickliness decreases. At 0 metres, the average prickliness was 226 while 2 metres up it was only 88 metres. This is to stop herbivores from grazing on the holly bush so the prickliness is higher to defend the bush against these herbivores.The holly leaves were longest at the top to get as much surface area for photosynthesis.

About Will Green

A student in England studying Automotive Engineering with Motorsport, Will created Ask Will Online back in 2010 to help students revise and bloggers make money. You can follow AskWillOnline via @AskWillOnline.

84 comments so far:

  1. Jimeney CricketMonday, April 25, 2011

    This is fantastic really helped with my ISA

    ReplyDelete
  2. Thank you so much, our teacher told us the wrong thing to do so this is really helpful (and evidence) lol :)

    ReplyDelete
  3. Well at least you know what the right thing is now! :)

    ReplyDelete
  4. omg!!!!! soooo gr8!!!!! helped me sooo much and can 'prove' to evry1 that i really DO no evrytin!!!!!!! lol!!!!!!

    ReplyDelete
  5. ur fantastic!!!!! xxx

    ReplyDelete
  6. Thanks so much i have my IAA today and it is great preparation.

    ReplyDelete
  7. It's alright and I wish you luck!

    ReplyDelete
  8. wow this website is the best thank you sooo much you are really cool and hope you carry on the good work
    hello pritvy

    ReplyDelete
  9. i approve of this site thank you everrrrr sooo much xxx

    ReplyDelete
  10. hey if we write all of this down will this get us full marks?

    ReplyDelete
  11. Yes you will be very likely to get full marks, that is if you remember it all!

    ReplyDelete
  12. I <3 this site

    ReplyDelete
  13. thank you, i got an A* in my IAA

    ReplyDelete
  14. I'm glad you feel this way about my site and well done!

    ReplyDelete
  15. Thank you so much! You have no idea to what extent you have helped me through giving out this information. I am very grateful to you, indeed. I joined the school recently and had an IAA with only 2 days to prepare and this site helped me get through it all. I am very thankful to you. (:

    ReplyDelete
  16. I'm so glad it helped you so much!

    ReplyDelete
  17. thank you so much :) i only found out my IAA was 2moz , but this has made me very confident :D thanks a bunch x

    ReplyDelete
  18. keena is part of the kkk

    ReplyDelete
  19. dis was well gud and elpfull lol thnks 4 evfin mate !!!!!

    ReplyDelete
  20. IM REALLY SMART KNOW THANKS TO YOUR SITE,THANKS FOR MAKINGME SMART

    ReplyDelete
  21. Hello all you hautlieus out there

    ReplyDelete
  22. Thank you...very useful :)

    ReplyDelete
  23. Cheers for this... really useful... King Pritvy, we know u... :)

    ReplyDelete
  24. Very good site, remember Jimmy, no copying this word for word, Hi Pritvy and Beau

    ReplyDelete
  25. Wow, I'm glad it helped you all :)

    ReplyDelete
  26. What about the disadvantages and advantages?

    ReplyDelete
  27. Where is part 2?

    ReplyDelete
  28. WILL PLEASE HELP IAA IS TOMORROWW!

    ReplyDelete
  29. Wow... IAAs soon, and I was just looking for helpful material I could regurgitate in IAA; I had no clue I was going to find the entire methodology for an IAA!

    It's not exactly the same as what we're doing, but God is it similar.

    Thanks!!!

    ReplyDelete
  30. hi, can someone PLEASE tell me the questions to the IAA and how do you write a plan for someone else, thanks very much.

    ReplyDelete
  31. Hi there,
    You will have to give me a bit more info than that as I done the IAA Feb 2011.
    The IAA's layout is quite consistand.

    Part 1 - Is the part where you plan an experiment out including the method, diagrams, equipment list, what as valid and reliable etc. (most of this article applied for part 1).

    Part 2 - This involves a similar experiment to part 1 but you have to plan it out for someone else. You cannot really revise as well for this part. The only thing you can do is learn all the terminology such as validity, dependant and independant variables and reliability. You can use some of part 1 to help you with that.

    Hope that helped.

    ReplyDelete
  32. Sorry, I can not give you any more information about that as I am going to the IAA on 2012 I am trying to look something up on the internet to try and revise before hand before I learn it in class. Thank you for the info, and also, if ypu can remember any questions in the IAA, please inform me. By the way, what did you get in you IAA's and overall grade in science. Thank you very much, you do not know how much help you are offering.

    ReplyDelete
  33. To be honest, I don't know how much I'm offering. This was just my revision notes. I did separate sciences (Biology, Chemistry and Physics) and got 2 A*s in Biology and Physics and a high A in Chemistry. For the IAA experiments, I got near full marks every time in every one. I hope that gives you some confidence in my articles on IAA on Ask Will Online!

    I can remember some questions on my IAAs.

    Part 1 - No matter how the questions was described, it wanted the same thing - a method for experiment including equipment etc... That was on the first page. The second page consisted on questions such as 'How did you make this experiential reliable/ valid? etc.' and 'How could you make the experiment more reliable/valid?' etc..

    Anyone's aim is to get full marks in part 1 as that is the part people revise for most (like this article is part 1). My tip which worked was to put as much information down as possible. Then, they won't be able to find any excuses to mark you down.

    Part 2 was always of some random kids (with really weird names!) conducting an experiment just like yours but a tiny bit different. For example, if part 1 was on Holly leaves experiment like in this article, the second part would be an experiment on height of rose bush affects prickliness (something similar but it can be slightly different sometimes). You then get asked questions similar to part 1, where you have to use knowledge to answer them. Again, write as much down as possible to stop the examiner having an excuse to mark you down.

    ReplyDelete
  34. Thanks, I know what you mean, do you have to use a curved line for the line of best fit on the graph. Thanks. (Hope I'm not annyong you with all these questions, I'm that type of person that likes to ask a lot of questions.)

    ReplyDelete
  35. Yes, for this graph it's a curved line of by fit. However, a line of best fit is just an opinion. If it looks like the points make a straight line, draw a line of best fits that is straight. If it looks curved, draw a curved one. Don't worry! Remember that I'm always here to help, your questions won't ever be annoying!

    ReplyDelete
  36. Thanks again, is this the same IAA that has been running for 2 years now as you done this on Feb 2011 and I'm going to be doing this on 2012.

    ReplyDelete
  37. It will 99% have the same layout to my IAA (part 1 and 2) etc.. However, I don't think the experiment will be the same but I wouldn't rule it out!

    ReplyDelete
  38. What subjects did you chose for 6th Form and what do you want to be when you are older.

    ReplyDelete
  39. I chose Maths, Physics, English Lit, Music and Business Studies A2. I always want to be a footballer when im older as I love the sport and have been scouted a few times by bug teams. I'd that doesn't work out, something in aerodynamist for F1 team or a musician composer or something fun!

    ReplyDelete
  40. Thanks for all the help, hope you wishes come true and well done on your grades, one last question, when you drew the graph in the IAA exam, did it look like the one you showed as above. Thanks, again, and have a very merry Christmas and have a happy and successful new year. If I need any more help, in any of the IAA's you offer, I will ask for help and stay in touch.

    ReplyDelete
  41. I didn't have t draw that graph for the IAA and it is likely you won't have to either. However, if I had to, it would look like one close to the graph above and thank you! Have a merry Christmas and happy new year too!

    ReplyDelete
  42. I've got my IAA tomorrow and like usual i've left revision until the day before,but this has helped me so much, Thank You! :)

    ReplyDelete
  43. Cheers Will! That's an excellent help. Much appreciated, thanks! :)

    ReplyDelete
  44. you have no idea how much i love you at this moment in time. our teacher cannot teach to save her life, half of the time our class is asleep. i also do separate science but at the moment i'm really stuck on mole calculations and what not, is it possible for you to do a page on Moles For Dummies ;D thanks again and good luck with your future plans!

    ReplyDelete
  45. Send me a message in Ask Will Online's contact page saying exactly what you need doing and I'll try and do it!

    ReplyDelete
  46. My IAA is tomorrow and now i have some hope of answering the questions, thanks to you. :) I would recommend your blogs to my science teacher for material to base her lessons on if i didn't know it'd get me into trouble. :P
    Thanks again!

    ReplyDelete
  47. OMG this is awesome!

    ReplyDelete
  48. Thanks This Was Awesome It Helped Me Alort xx

    ReplyDelete
  49. Will do you have a bar graph version of the line graph used in this experiment?. pls reply fast.

    ReplyDelete
  50. finally... a helpful website!
    thanks a lot

    ReplyDelete
  51. No unfortunately Matt, I have only used a line graph as it best records the results. Why do you need a bar graph? From my memory, I never had to use a bar chart for this experiment in class or exam, that is if you are doing the IAA?

    ReplyDelete
  52. Is it a bar chart or something?
    Also, how should I conquer the second method.
    I feel so stressed! :(

    ReplyDelete
  53. Sorry, you will have to give me more information.

    ReplyDelete
  54. Will Helpm me :'( basically, would u just go through withus the main things you do to get your a* etc....
    and also do u need to be really pricise in your methods to get the upper bands>

    ReplyDelete
  55. argh great but my friends who have already done the iaa say that there are two methods, one to measure the damage and the one you have displayed
    meh but thanks

    ReplyDelete
  56. To get an A*, you need to go into the littlest detail: the more detail the better. Also, try to always write more than less as you can't get penalised for writing the wrong things: only the right. Precision is key for your method. Take into account hp the reliability, validity and accuracy of your method at all time.

    The first part of the IAA is about an experiment you have done in class. For example, the experiment I did in class was this one about holly leaves prickliness. You can revise for this.

    The second part is of an unknown experiment that has similarities to the first experiment. For example, your friends experiment ws about the damage of holly leaves (I am guessing). This is harder to revise as you don't know what the experiment is. For this part, always remember detail, validity, reliability and accuracy.

    Hope this makes sense and helps.

    ReplyDelete
  57. im confused, my title is the same as yours

    how the height of bush affects length of leaf and prickliness

    but we didn't times the longest prickle by the amount, we just took the average amount of prickles, i don't understand why , our objective and aims are the same.

    did our teach us wrong, or is average amount of prickliness ok for the prickliness

    ReplyDelete
  58. To make things easy look at it in this way.

    The prickles on a holly leaf may be the same anywhere on the bush I.e. each leaf has 7 prickles. But, further it the ground, the prickles are longer to stop animals fro, eating the bush. Using your method, you wouldn't be able to tell that the prickles get longer the closer to the ground.

    The best way to work out the prickliness is to measure the number of prickles on the bush and times it by the average height of the prickles. However, this will take ages therefore by measuring the tallest prick, you can still get accurate and reliable data.

    ReplyDelete
  59. thanks for the a*. it was all because of you. :)

    ReplyDelete
  60. fantastic thanks

    ReplyDelete
  61. Hi, I just wanted to you to exmpain the point in the valid section when you said "when we measure sample". I'm not quite sure what that means, it might be the way you wrote it, so can you please explain it to me. Thanks.

    ReplyDelete
  62. I was referring to the time which we measured the leaf as in winter, the leaf size may decrease compared to a leaf size from the same bush in summer. Does that make sense?

    ReplyDelete
  63. Yeah, thanks very much.

    ReplyDelete
  64. how would you answer the question "How can you improve the experiment?" can you please give me some tips?

    ReplyDelete
  65. Can you please give me some tips on how to answer the question "how can you improve your results?"

    ReplyDelete
  66. Can you please give me some tips on how to answer the question "how can you improve your results?"

    ReplyDelete
  67. Can you please give me some tips on how to answer the question "how can you improve your results?"

    ReplyDelete
  68. When you say improving, you are referring to how you make the experiment more accurate I hope. You can therefore repeat the experiment even more times, measure to more decimal places and even take into account the uncertainties of the experiment.

    ReplyDelete