Edexcel IAL Biology Unit 5 (WBI05) Scientific Article Discussion - June 2016

Does anyone have the specimen paper to send to me?
plspls x

Yep that's correct! Spearman's Rank tests for correlation within a range and plotting anything with a range of values would be plotted with a line graph or scatter graph (although line is better). T-test and Mann-Whitney are used more for differences between two or more variables, so like testing vit C content in multiple foods, testing males against females, or testing 2 different fields, etc). Makes sense?

Okay so I've seen alot of people around here wanting to know the predictions for June 2016 paper, although I'm not a paper-setter so I can't be very certain but here's what I came up with
AS practicals:
1.Effect of caffeine on heart rate of daphnia- Jan 2012(Q#2)
2.Vitamin C content of fruit juices- Jan 2013 and June 2015
3.Effect of temperature on permeability of membranes-June 2010
4.Enzyme concentration and rate of reaction-Jan 2011,Jan 2015 and Jan 2013
5.Observing mitosis-Jan 2016
6.Totipotency and plant tissue culture-(never)
7.Tensile strength and plant fibres-(never)
8.Investigating plant mineral deficiencies- June 2013/ Specimen paper IAL
9.Antimicrobial properties of plants-Jan 2014

A2 core practicals:
1.Looking for pattern (ecological studies)- June 2010, Jan 2011 and June 2012
2.Effect of temperature on hatching rate of brine shrimps/germination- June 2011
3.DNA Gel Electrophoresis-(NEVER)
4.PCR- Jan 2014
5.Effectiveness of antibiotics- Jan 2011, June 2012 and June 2015
6.Measuring rate of oxygen uptake- Jan 2012, Spoecimen paper GCE and Jan 2015
7.Investigating breathing- June 2013
8.Can Snails become habituated to a stimulus?- June 2014

Well, so the expected topics for this paper (the ones that have never showed up earlier are Electrophoresis, Totipotency and tensile strength).One of them is definately gonna show up!
But please don't kill me if it doesn't! I'm just as clueless as you people hehe

You guys! I need help! Can someone tell me how to answer the 10 mark question in unit 6b please help!

One little question peeps..
When we write a null hypothesis, we write something like "There is no significant ..... between ..... and ......"
So, when we write a hypothesis do we write "There is a significant ...... between ...... and ......"
or do we write "..... has an effect on ......"???

You follow the procedure for measuring the Vitamin C content by using DCPIP indicator.
First, you take Vitamin C solution of known concentration and add it using a pipette to the same volume of DCPIP (say 2cm^3) you will use for the duration of the experiment. Find out the volume required to decolourise the DCPIP.
Next, you cook the vegetable, keep them warm and you may either crush or blend the vegetables and obtain the extracts.
Independent variable would be the length of time food is stored after cooking.
Then include what times you're going to use like 0 minutes (which would mean as soon as it was cooked), 3 minutes, 6 minutes, 9 minutes and 12 minutes (you can use your own time intervals)
Dependent variable would be the Vitamin C concentration
So as the procedure states, you take a known volume of DCPIP solution (2cm^3) in a measuring cylinder and you add drop by drop of the veggie extract with a pipette, recording the volume required to decolourise the DCPIP at each time interval.
You write about two other variables that would affect the result and how you would control them.
Repeat several times.
Finally, you can find the Vitamin C concentration of the cooked vegetables at each time period by using the formula
Concentration=
(conc of Vitamin C used x Vol. of Vitamin C used) /Volume of veggie extract used


Here's the markscheme
https://3ef7e8cb3a958922c328db7b6aaff7930fa6bc87.googledrive.com/host/0B1ZiqBksUHNYblNnNmlSS3RWUm8/June%202015%20%28IAL%29%20MS%20-%20Unit%206%20Edexcel%20Biology.pdf

The newer papers as in these IAL ones give medians and range as well. And they even gave this chi-squared test aswell!

Actually totipotency came in one year, it was to investigate the effect of something on plant tissue

Posted from TSR Mobile

What if they give us gel electrophoresis.What would be the Dependent and independent variables for it?
i was thinking and maybe they could give us something to do with cystic fibrous and use the chi squared test since its comparing results of observed and expected.
the punnett square can be drawn for the genotype of the unborn baby.This would be expected.ALSO this would only be the case if one of the parent is affected and the other is a carrier or both are carriers.

now we carry out the gel electrphoresis of the amniotic fluid obtained,the bands matching which parent will determine whether the baby is affected or not.
lol this is just my own theory,prolly wont come up as we don't know anything about the other variables.

Oh, Thank you

Oops this seems to be a hard one! I hope this doesn't come up :/
Well I was thinking about this so I guess these things would do but not really sure
Dependent variable: The distance moved by a DNA fragment
Independent variable: Length of DNA strands
Standards:
1) agarose density
2) voltage
3) buffer characteristics
4) temperature (the chamber does get warmer during the run)
5) time

Umm, for control we'll probably write: Petri dish with gel and buffer but no DNA

And I have an instinct that this might show up related to crime scene and all.

A DNA strand consists of many genes that code for specific amino acids right?
So the scientist decided to examine ONLY 5 genes that are different from each other.
I hope that makes sense.

Does this seem reasonable for Q#1?

What if they give us gel electrophoresis.What would be the Dependent and independent variables for it?
i was thinking and maybe they could give us something to do with cystic fibrous and use the chi squared test since its comparing results of observed and expected.
the punnett square can be drawn for the genotype of the unborn baby.This would be expected.ALSO this would only be the case if one of the parent is affected and the other is a carrier or both are carriers.

now we carry out the gel electrphoresis of the amniotic fluid obtained,the bands matching which parent will determine whether the baby is affected or not.
lol this is just my own theory,prolly wont come up as we don't know anything about the other variables.

Hey guys! Can anyone explain to me why we need to control temperature in the tensile strength of fibers experiment? As in what is the effect of temperature on tensile strength of fibers?

Also, What is the dependent and independent variables of the Mitosis experiment?