2010 biology unit three exam

[Keine]

It may not exactly be ideal for temperatures to remain around 120C
in a washing machine
Washing clothes with a high temperature wouldnt be recommended
due to the possibility of shrinkage of clothing, so realistically
and practically, it would not be ideal for C to be the answer :\
though, there is nothing that says you have to take into account
of 'the practibility of the enzyme', so you may still be correct

[shinny]

It may not exactly be ideal for temperatures to remain around 120C
in a washing machine
Washing clothes with a high temperature wouldnt be recommended
due to the possibility of shrinkage of clothing, so realistically
and practically, it would not be ideal for C to be the answer :\
though, there is nothing that says you have to take into account
of 'the practibility of the enzyme', so you may still be correct

I'm not saying that you should be washing at 120C, but at least it is able to. In saying 'best', something that is at least able to wash at 120C would be 'better' than something which outright can't because it ends up denaturing. It's just the most flexible enzyme, and given the lack of any other available information there, I think this flexibility is what they're aiming for in the question given that enzymes don't denature when going to lower than their optimal temperature. It also has the best pH range which allows for both acidic and basic pH's - no other enzyme allows this. But yeh, obviously this is all based on speculation too, I really don't know what VCAA was aiming for either, but this is just my justification for an answer.

[simpak]

But you never wash at 120 because you don't want your clothes BOILING.

[Russ]

I still maintain it's J (option A) because it has the widest range of optimal conditions, but I can tell nobody is going to agree until the examiner's report is released.

[mikee65]

Yes but the absorption graph of chlorophyll is divided into two peaks, one for c. a and one for c. b.
I stick by red because c. a. absorbs red and is the main pigment in photosynthesis, whereas c. b. is only an accessory pigment.
I would also add that just because c. b. absorbs more of a particular wavelength does not mean that the amount of c. b. present in the leaf is greater than that of c. a.
There may be a lot of c. a. in the leaf and a little of c. b., which would mean the plant in the red light would photosynthesize more efficiently.

Hmm yeh, my quick Wiki and google image search said that it was blue but having read further, chlorophyll A is primarily involved in photosynthesis and absorbs more red as you said. I really have no idea now. Hurrah for VCAA.

EDIT: Apparently B is also found more so in land plants, not aquatic ones like the question was referring to. Also weirdly enough, Wiki also has this graph which appears quite wrong. Is Wiki wrong for once? 

i remember reading some were that chlorophyll A is the only photosynthetic pigment and B and cartenoids just assist A i think so reds more efficient?

[crayolé]

^^^ ^^^
Yeah i remember reading that too, carentoids just absorb the energy for clorophyll to do its magic

[Plague]

My Bio teach told us it was Blue for the photosynthesis question. I was happy coz I wrote blue. He might be wrong though.

As for the washing machine one, I wrote J as well (Temp = 10-30 deg. and pH 7.0-9.0) for about two reasons.
1. Water has pH 7.0 and although I'm not sure about pH of detergent, it is going to be alkaline so greater than 7.0. If it gets mixed around in water, shouldn't the overall pH go slightly higher than 7.0? That was my reasoning anyway, probs wrong
2. Temp, I heard somewhere you can use cool or warm dry for washing clothes? It would suit it then if the optimal varies between 10-30? Of course this is probably wrong since it will denature if temps get any higher which they most likely would.

It's times like these I wish I did more chores. I don't think they should be allowed to take marks off for this question; hell if I know how a washing machine works >.>

[simpak]

Kay guys, can I just like, give you another item of logic.
Say blue light is most efficient.
Would you not expect plants to appear yellow?  Colour opponency says yes.
The fact that plants are green really does kind of point out that absorbing red light is most important.

@Plague Your reasoning for the pH of the water is actually very good.  The pH of most detergents is around 10, but with a whole washing machine of water and only a spoonful of detergent, we could assume that it was just above 7 rather than three whole points above on the scale.

[shinny]

Regarding A for the washing machine question, I'd agree with that on practical reasoning. However it doesn't really show any biological reasoning whatsoever. The reasoning I put forward for C uses the difference between temp and pH denaturing as I said, so it really comes down to whether VCAA is more interested in testing your knowledge of washing machines or of enzyme function.

[lexitu]

Agree with Shinny.

Also how do we know the plant is green? Perhaps it is red, perhaps it is a new species discovered this year and is rainbow coloured. It is ridiculous to make us generalise, especially when there is no obvious way to discern validity between the options they have given us.

[shinny]

Yes but the absorption graph of chlorophyll is divided into two peaks, one for c. a and one for c. b.
I stick by red because c. a. absorbs red and is the main pigment in photosynthesis, whereas c. b. is only an accessory pigment.
I would also add that just because c. b. absorbs more of a particular wavelength does not mean that the amount of c. b. present in the leaf is greater than that of c. a.
There may be a lot of c. a. in the leaf and a little of c. b., which would mean the plant in the red light would photosynthesize more efficiently.

Hmm yeh, my quick Wiki and google image search said that it was blue but having read further, chlorophyll A is primarily involved in photosynthesis and absorbs more red as you said. I really have no idea now. Hurrah for VCAA.

EDIT: Apparently B is also found more so in land plants, not aquatic ones like the question was referring to. Also weirdly enough, Wiki also has this graph which appears quite wrong. Is Wiki wrong for once? 

i remember reading some were that chlorophyll A is the only photosynthetic pigment and B and cartenoids just assist A i think so reds more efficient?

Yep, that's what mavis and I (eventually; not trying to take credit for your work mavis ) were trying to get at. Answer should technically be red then.

^^^ ^^^
Yeah i remember reading that too, carentoids just absorb the energy for clorophyll to do its magic

If this was in a textbook, then the question is fair game I guess.

[Keine]

I agree with whomever suggested that the person
who wrote these ridiculous misleading questions
should be shot.

[crayolé]

I agree with whomever suggested that the person
who wrote these ridiculous misleading questions
should be shot.

I shotty doing the shooting

[Keine]

I agree with whomever suggested that the person
who wrote these ridiculous misleading questions
should be shot.

I shotty doing the shooting

please do : )

[Jdog]

ph of washinng machine water is 10-11, my freinds mum , works for napi san company... and so i think she would know. and she said  although 10-30 is porbably the most common, washing at 40 is also very commmon.