biology work

aerobic respiration in plants and animals e.g. germinating seeds and mealworms
Bio Experiment : Comparing Rate of respiration in mealworms at different temperatures?
Mealworms are cold-blooded animals and are unable to maintain a constant core temperature, hence respiration would therefore change with temperature. As glucose is oxidised, oxygen is used up and carbon dioxide and heat energy is produced. Increment in temperature / production of CO2 or O2 consumption would hence be good indicators for the experiment.

1) Hypothesis

[What other statements can I make, other the ones they mentioned about in the preview of the experiment?]

2) Procedures
a) Weigh a mealworm and record its mass (0.61g).
b) Set-up: Put 5 NaOH pellets into an Eppendorf tube. Place in inverted into a testtube. Place a layer of netting over it. Put the mealworm into the test tube. Put into water bath. Make sure that water level is higher than worms can reach. Set up respirometer and connect to test tube when temp. stabilises.
c) Record original volume reading of water in syringe, then every minute, record, the rate of decrement.
d) Calculate rate of O2 consumption
Additional Details per gram mass.
And finally, draw a conclusion.

So theoretically, how is it supposed to be like? I don';t even know how to plot a graph. My expt results are normal, I did it by myself and asked the teacher.

Points asked:
1) What variables are controlled/indpt/dpt?
2) What is measured in order to monitor variables?
3) How are controlled variables kept constant and how is indpt variable changed to obtain addtl sets of data?
4) Explain how movement of H2O level in tubing indicates oxygen consumption and how u will use data to obtain O2 consumption per gram mass.

PLEASE ADDRESS THESE QNS too (very impt) - I'm considering to add such points into my report. Additionally, how do I plot the table? :DD can anyone send an attachment of an email to [e-mail] :DD thanks alot.
5 years ago
Oh yea, not forgetting. Could anyone explain to me the uses of the sodium hydroxide pellets and how does the setup affect it ultimately?

T_T somehow, this is graded. and the teacher doesn't even tell us the use. I can only like assume that the sodium hydroxide pellets are used for absorption of Co2. my guess.
5 years ago
Aerobic Respiration IAA
Ok so those of you familiar with the edexcel GCSE exam board, we have to do these assessed practicals, and the one I'm going to do in biology is apparently one that has never worked, in all the years that it has been around apparently even the exam board couldn't make it work when they went on a conference in Malaysia. The experiment is as described below:

The aim of the experiment is to find out how temperature affects aerobic respiration.
So the method in which we are going to test this will be using mealworms (the exam boards idea). Basically we are going to take the mealworms and place them into different beakers. So basically I think it would be about 5 meal worms to a beaker.
Then we would place the beakers in several water baths ranging from 10degrees to maybe 80degrees, depends on how many we can get (at 10degree intervals).
The idea then is to measure the amount of respiration by sealing up the beaker. Then inserting capillary tubes into the sealed beaker. The capillary tubes were preprepared with ink in them so that we can measure the rate of respiration in each of the beakers.
Okay so assuming that 40degrees is the optimum temperature, then the ink in the capillary tube for the beaker will have moved the most.
But for some reason it doesn't work. (The exam board decided to stick with this dumb experiment even after THEY tested it and still failed.

So does anyone have any clues on what went wrong, any thoughts?
I did this exact experiment for AS level biology 7 years ago. It worked. It worked very well.

My thought is that the equipment used wasn't good enough. You have to make sure that you have a good enough seal so that no air can escape AT ALL.

I can't remember the exact apparatus we used though - I think it was something smaller than a 50ml beaker (and a muslin bag was involved somewhere), and used more than 5 worms - possibly we used boiling tubes. The experiment was left for quite a while too - at least 3 hours, maybe over night.
I see...
Thanks for the advice.

I can see a couple of problems, part of the oxygen used up is replaced by an equal volume of CO2, so the change in volume won't be as big as you expect.
Also I wonder if, like termites and people (among others) mealworms produce methane.

Also, of course, without a perfect seal, this simply won't work.