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passive active transport, h2o transport tree, bacteria, exam

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passive active transport, h2o transport tree, bacteria, exam

Postby Zamzen » Mon Oct 18, 2010 9:25 pm

So we had a few exam questions and i feel that i did not get enough points on the exam, points that i feel that i had earned. this is highschool biology.

One of the questions is rated as the criteria A+ and gives 3 points.

The question asks the differences between active and passive transport.

I pointed out that active is against the natures will and passive is not. active requires energy passive does not. active goes trough protein channels passive trough fosfolipid layers. i related it to the laws of thermodynamics that active is not spontanous but passive is. i also threw in that active transport gives rise to the membrane potential which opens and closes some protein channels. My teacher gave me 1.5/3 and his reasoning was that i did not bring up endo and exocytos. I stated that that this was more than enough to answer the same question which even included the similarities about active and passive transport. To be honest the book basically did not state endo and exocytos, it did not state membrane potential or relate it to spontanous process. me and my teacher agreed to that since i did throw in something extra such as the membrane potential i did recive 2.5 points total for this question out of 3. But i still think that i deserve the full 3 points, what is youre opinion?

The next question gave 3 points as well and is a A+ question
The second question which i argued with my teacher about is to describe detailly how water is transported in a 27m tall tree. I clearly stated and described that it has to do with hydrogen bonds as well as sun energy which cause the water to condensate at the cleaveopenings causing the entire water chain to be pulled up from the cleave openings down to the roots. i stated what the xylem was built up of (dead cells which water also makes hydrogen bonds with) and what it was. on top of it i stated that water travels in to the roots by the process of osmosis.

Again in the book i covered more than well everything to recive full points, and how the water actually goes in to the tree is not asked in the question.
I recived 2 points since my teacher said that i did not explain HOW the water EXACTLY gets in to the three, my response was that he did not ASK how water gets in, he asked how water travels inside the the whole tree. And i do know that the roots pumps out protons to take in ions so that water diffuses in to the roots but this was not the question and thats why i threw it in vaguely in my response to the question. Now the other thing is that i told him how the water gets in should not be a whole point deduction since the hydrogen bonds as well as the xylem part and on top of it the claveopening part + the sunenergy point should be the whole 3 points. It ended up with me getting 2.5 points for the question. Altough i belive the same thing here, that i did earn the full 3 points.

The third question is an A+ question as well worth 2 points.

It asks what the downsize is with the overabuse of antibiotica. (ex mass feeding to pigs etc)

I described antibiotica troughly to give some background information, i pointed out that super bacterias are created that get resistant, i pointed out how the chemical companies change the antibiotica molecule, i stated how the bacterias exchange theyre dna plasmids so that there would be more super bacterias, and i ended the answer with that eventuellay there would be alot of bacterias causing disaeses that we cannot kill with antibiotica.

i recived 0.5 points for this!
i talked with my teacher who agreed with me that i did bring up important points such as the super bacterias as well as the resistance part. and managed to recive 1/2 point. he stated that to earn more points i should have brought up another subject to why the over abuse of antibiotica is dangerous.

i hope a high level biologist can help me with this because i was 1.5 points away from an A which i managed to get when i talked to my teacher, but i also want to know if i earned them as well as if i could have earned more than those.

Im thankful for all the help that i can recive!

I would like to point out that my this is the first class my teacher has had so he is fresh from the university. As well as that he had made misstakes in class. I would also like to point out that he is a very very good teacher as well.
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Postby JackBean » Tue Oct 19, 2010 9:24 am

well, you're bringing up lot of stuff, not always relevant and not always correct. Only for that, I would get off some points.
However, I think you migth get some points for the last question. Did he tell you what he meant by the other subjects?

And BTW by complining about the teacher, you will not get anything, only the teacher mad ;)
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Postby Julie5 » Tue Oct 19, 2010 10:01 am

Hmm, I get the feeling your answers are simply not repeating what is in your textbook. Tsk tsk. All that 'thinking for yourself' is not good for most examiners!

In general, having a newly qualified teacher has its pros and cons. The cons are that they tend to be unsure of themselves (or worse, sure of themselves!!!), and are still 'reading' the class - maybe the teacher is trying to get a feel for whther you are genuinely enthusiastic about the subject, or just trying to challenge his authority and knowledge and be a general smart-axx!

The pros are that they are fresh out of tertiary educatoin themselves (or switching in fronm industry), so are keen and unjaded and, hopefully ,plumped full of 'latest theories and results' so you will get hold of the latest thinking in the subject from them.

My suggestion is to do your best to work with the guy, and not seem to challenge him, or 'prove him wrong'. If he feels you are 'on side' s/he will cut you more slack. Try and turn it into a discussion, if necessary, but don't come across trying to contradict him ('You're an idiot sir!') or take up too much of his time (ie, he's got other pupils to deal with.) I think your best approach is to show real enthusiasm for the subject (which you seem to have!), and tap into what we hope is his enthusiasm for the subject!

Good luck!
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Re: passive active transport, h2o transport tree, bacteria, exam

Postby audushuxley » Tue Oct 19, 2010 10:22 am

Hi, I also got 27,5 on the exam.

I agree with your sentiments that it seems that the marking was overly critical. The antibiotic question being a case in point.

Overuse of antibiotics leads to resistant bacteria. Resistent bacteria cause infections that can then not be treated with current antibiotics. Antibiotics are derived from microorganisms. They are not "created" and therefore there is a limited range of differing antibiotics available.

I would have thought that was more than adequate to earn three points but nope, I received 0,5. Are we supposed to write about the collapse of society in the event super-resistant bacteria become commonplace?

As for the tree I did mention that ions are actively pumped into the root system, this decreases the water potential in the root system and leads to an influx of water molecules over the semi-permeable membrane. I didn't get all three points though.

I'm not really sure how one can be expected to raise endo/exocytosis as part of a question on active/passive transport. Several reasons:
- There was a question at the beginning that asked for clarification around the concept "endocytosis" not that this mean endocytosis is excluded but it does show that the student has knowledge of the process.
- There were three marks available for the question. I interpreted it in the exam as, 1 point "active transport requires energy, passive transport is a spontaneous process", 1 point "active transport is against a concentration gradient" and 1 point "proteins use energy rich carrier molecules to "pump" the required molecules/ions over the phospholipid membrane"
- The book doesn't raise this connection and in all fairness we have two hours of tuition a week.

As a side note I think you are doing yourself a disservice by describing the question as A+. If you compare with the A-level system in the UK, MVG equates to A. A+ is a new higher qualification that has been introduced this year. The A-Levels are far more in depth than than the "equivalent" Swedish educational programs. In the UK one can expect to study a maximum of 4 subjects over two years as opposed to 10 or 12 subjects over 3 years in Sweden. In short, MVG in Sweden is not the same as A+ in the UK. :)

As for the jackbeans comments. Yes, it is important not to complain. But, it also important to discuss any issues with the teacher, as part of this discussion you may discover a better approach to learning the course material or the teacher may realise that they should have awarded points based on the material and curriculum that is being followed. Either way, the end result is nearly always positive. Dialogue is better than silence. :)
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Postby JackBean » Tue Oct 19, 2010 10:40 am

I didn't say to be silence, but the last part did sound pretty much as complians, but by that he won't get anything.

Anyway, to be honest, your answers do not seem much correct to me.

1) antibiotics are primarily produced by bacteria (oh, really bacteria? Do they kill themselves?), but there are plenty of half-man made antibiotics, which take the overall structure, but modify the small groups, so they avoid resistance (e.g. look to beta-lactamase group of antibiotics; yes, penicillin)

2) what semi-permeable membrane?

3) just because it's part of other question or is not mentioned in the book doesn't mean, it's not active transport.
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Re: passive active transport, h2o transport tree, bacteria, exam

Postby Zamzen » Tue Oct 19, 2010 2:51 pm

My teacher will go trough the test on thursday and i need to be prepared!

About the bacteria he did agree afterwards that i did earn at least 1 point there, but i need to be able to prove that tomorrow as well.

The tree part clearly stated "How is water transported to all parts of the tree" worthy of 3 points.
i recived 1.5 points and afterwards an extra point. this is my conclusion to what i will bring up tomorrow.

1. dividing the most important things into half points. so bringing up 6 things worthy of 0.5 points each and explaining why. amoung these 6 esseential things i brought up 5 of them.

1. cleave openings, without them water will not be able to reach all parts of the three
2. sun energy, causes the water to condense at the cleave openings
3. the xylem where the water is transported
4. the hydrogen bonds created by the water moleucles
5. the osmosis of the water into the tree roots
6. the pumping of the protons so that ions travel inside the tree roots.

my weak point here is question 5 and 6. i did state that water travels in trough osmosis. on the other hand i did not explain the exact mechanism. now what im going to do here is to state that you can not mention the proton pumping part, without throwing in the osmosis of water in to the tree roots since it wouldent be any point of doing so. meaning that if you just mention that protons are pumped out with active transport so that the tree can take in ions is, in it self not a good explanation to even earn these points. you need to throw in the part that water enters the roots with osmosis so it is worth at least 0.5 points.
what im trying to pull here is that i at least mentioned how the water gets in and that it self should be worth 0.5 points, and the mechanism behind it another 0.5 points.
i did explain everything else very well on the test. and you can not state that subject 1-4 is worth anything less than 0.5 points since you need these critical parts to answer the question. which leads me to the conclusion that question 6 should be worth less! than the 1.5 points deduction that my teacher originally gave me, and place it at a point level of 0.5.
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Re:

Postby Zamzen » Tue Oct 19, 2010 6:43 pm

I did ask him if you could get any form of point deduction for bringing up non relevant things as you mentioned and he did say no. Jack bean, you mention that endocytosys and exocytosis is a form of active transport but the question did not really state what they are used for. the question stated the differences, and i feel that since the active transport give rise to the membrane potential it is a difference and should be worth more than what forms of active transport there is.
because if the question would have stated something like "what is active and passive transport used for" you could have said for example endocytosys etc.
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