Multiple Choice (3 Viewers)

[sslions]

I got the following:

1) C ('D' seems to be the correct answer. If you ask me, the question sort of contradicts the meaning of an enzyme - a biological catalyst that BREAKS DOWN molecules to help speed up reactions. If the arrows were facing the other way, it would have made much more sense/logic, and then C would have definetly been the answer).

Biological catalysts don't only break down molecules; they can provide an active site where substrates can react together. Thus the enzyme can combine substrates together to form a product; these are called anabolic reactions, like anabolic steroids where substrates react together to form larger proteins for muscle growth.

 

[Punksta07]

Note that the more salt that is in the body, the more water that will be in it. Thus the answer with aldosterone and ADH was: Aldosterone and ADH. Aldosterone affects salt, which apparently affects water concentration as well as ADH affecting the amount of water re-absorbed.

Everyone seems to have a misconception of what the main function of ADH and Aldosterene really is....You have to look at it from blood concentration levels...During Dehydration, there is less water in the body, thus blood concentration levels are high, the release of ADH occurs when the Hypothalmus detects an increase in blood concentration this means ADH is relased and Aldosterene is inhibited because "if there is an inceased blood volume and pressure, the output of Aldosterone is reduced - "Heinemann Biology Page 263"

Simply, ADH relased, Aldosterone is inhibited

 

[philipadams123]

15 out of 15 according to the forum

but i stuffed genetics, did a dihybrid cross at the start

but lookin for a 90+ raw mark

 

[ChrisAlli]

My answers

1. D (C was the enzyme as it remained unchanged at the end of the rection and A+B was after the substrates have reacted therefore it had to be A & B)
2. B (simple)
3. A (pretty sure it's the Xylem)
4. C (can't be B or D and the soil in the area of the pines would be free of fungus otherwise the trees wouldn't be growing there)
5. D (changed it from B, didn't really know as I hadn't seen this type of question before so probally wrong)
6. B (simple)
7. D (simple)
8. D (simple)
9. D (simple)
10. A (simple)
11. B (simple)
12. A (simple)
13. C (simple)
14. A (I put A but could of well been C I wasn't sure it was a toss up)
15. B (simple)


porbally 13/15 which is OK I guess

 

[emoslitorist]

14.A (I'm not sure about this one; my friend says C)

Aww, I put in C.

My answers were the same as yours except for that one.

 

[lincoln.liu]

13C - populations are exposed to environmental pressure and favourable traits are passed on from naturally resistant individuals. D states that the pop. adapted, supporting the inncorrect 'Lamarack theory'. WE are taught the Darwin/wallace....

 

[Buiboi]

^^^^ yeah i didnt like that one
was that the one that gave you an option of
some of the original population were resistant
and
some of the orginal population adapted to survive?
i selected teh 2nd optio nbut im sure its wrong..ah well..one mark

oh yeah, if you remember addisons disease; which was caused by a damaged adrenal cortex, responsible for secreting aldosterone, the major symptom of it was 'severe dehydration' so it woudl be reasonable to say that both adh and aldosterone were released

 

[Punksta07]

Okay, Have you ever done excessive excercise and not drink water then later find out your urine is highly concentrated, thats because it is high in salt ions which is lost due to less aldosterene being released (as aldosterone helps in absorping these ions back). Ask any medical practioner on what is the major external symptom of dehydration and they will tell you "concentrated urine" after excessive excerise. Yet still it could be both depending upon the context it is in (like addisions disease) but with excersise im thinking its A. Lets BOS decide the answer,, not us

 

[*Han]

My answers

1. D (C was the enzyme as it remained unchanged at the end of the rection and A+B was after the substrates have reacted therefore it had to be A & B)
2. B (simple)
3. A (pretty sure it's the Xylem)
4. C (can't be B or D and the soil in the area of the pines would be free of fungus otherwise the trees wouldn't be growing there)
5. D (changed it from B, didn't really know as I hadn't seen this type of question before so probally wrong)
6. B (simple)
7. D (simple)
8. D (simple)
9. D (simple)
10. A (simple)
11. B (simple)
12. A (simple)
13. C (simple)
14. A (I put A but could of well been C I wasn't sure it was a toss up)
15. B (simple)


porbally 13/15 which is OK I guess

15 can't be B, Morgan improved out knowledge of sex linkage. 15 is D

i got...
1. C (but im very sure its D)
2. B
3. C (also wrong, its A)
4. C
5. B
6. B
7. D
8. D
9. D
10. A
11. B
12. A
13. C
14. A (still not sure about this one)
15. D

so... 12 or13/15

from what i've seen most people did pretty well. it wasn't too hard, i just made a few stupid mistakes

 

[craig123]

i do beleive 14 is c and the reasoning is this,
adh stands for anti diuretic hormone with diuresis meaning loss of water through urine, so antidiuretic.... (should be obvious)
but for aldosterone, it works to decrease pottasium ions reabsorption and increase sodium ion reabsorption, and water follows by osmosis as it follows the sodium ions. The arguement that a person who is dehydrated has highly concentrated urine and hence aldosterone is inhibited is wrong for two reasons. One: there is less water in the urine so of course its goin to have a higher salt per centage and this is independent of whether less salt is being asorbed by the kidney. Two, a little less obvious: pottasium is a salt too so if we decrease pottasium ion reabsorption, one type of salt, and increase sodium ions, another type of salt, then there should be no increase in salt excretion.... which brings me back to my first point. less water excreted but same amount of salt mean more concentrated urine, or if you want to find a chemistry text book concentration= amount of substance/ volume

 

[craig123]

oh and i forgot to mention that i thought 3 was d as i thought those rings were sieve plates but im not sure now, but since it is made more explicit that phloem have seive tubes then any rings on xylem vessels in my textbooks and on websties i thought they were trying to point to it being phloem

 

[Buiboi]

The rings are actually dead cells in the xylem, the other columns that yo usaw were mineral ions and water, i read this somewhere, but then i saw this same diagram, this was the diagram i had in my notes under xylem

 

[mithril1337]

oh and i forgot to mention that i thought 3 was d as i thought those rings were sieve plates but im not sure now, but since it is made more explicit that phloem have seive tubes then any rings on xylem vessels in my textbooks and on websties i thought they were trying to point to it being phloem

That's exactly what i was thinking T.T

lets hope were right gl

 

[Punksta07]

That's exactly what i was thinking T.T

lets hope were right gl

I thought they were pointing at xylem cells since a longtindual view of them show "double or single ring spirals of lignin". If you have the "Heinemann (second edition) Biology Activity Manual" Go to page 110 and they have the same diagram (labelled) that was given in the test...lucky for me i memorised it...But as i have stated before...saying whats right or wrong doesnt make a difference, BOS will show us the answers in 2 months...im probably wrong...who cares, just wait.

Goodluck People for your remainign exams.

 

[Punksta07]

i do beleive 14 is c and the reasoning is this,
adh stands for anti diuretic hormone with diuresis meaning loss of water through urine, so antidiuretic.... (should be obvious)
but for aldosterone, it works to decrease pottasium ions reabsorption and increase sodium ion reabsorption, and water follows by osmosis as it follows the sodium ions. The arguement that a person who is dehydrated has highly concentrated urine and hence aldosterone is inhibited is wrong for two reasons. One: there is less water in the urine so of course its goin to have a higher salt per centage and this is independent of whether less salt is being asorbed by the kidney. Two, a little less obvious: pottasium is a salt too so if we decrease pottasium ion reabsorption, one type of salt, and increase sodium ions, another type of salt, then there should be no increase in salt excretion.... which brings me back to my first point. less water excreted but same amount of salt mean more concentrated urine, or if you want to find a chemistry text book concentration= amount of substance/ volume

Yes thats true though Aldosterone and ADH do play a role in urine concentration and since the question did put us in the context of dehydration..they wanted us to link the two...either way your prob right but i read it in the heinemenn text book (made a specific reference on my previous post) on which they gave an example on what occurs with ADH and Aldosterone during excessive excersise. They might be wrong too so lets all wait until the lovely answers are released so we actually learn something correct for once!

 

[squeak29]

I liike you guys saying BOS will tell us the answer and we'll see whos right......you only get marks not how much you got in each section OR the specific answers for questions so really you will never know UNLESS someone gets 100% as a raw mark and you can ask them their answer =P


Oh and for 14 i put C simply because i was reading some ADH thing before the exam and i read that both were released but i couldn't remember why....seems like i made the right choice

 

[shanti96]

I put 14C b/c I had a similar question with similar circumstances in my trial exam but I only put ADH and got it wrong... I hope I won't get this one wrong!

 

[mitch0816]

1. D - I believe the substrate is the reactant, not the product.

Yes, the substrate is the reactant, not the product. but D is a product and C is the substrate. so im pretty sure the answer is C.

4. C - Prevention is better than cure.

For this i put D for quarantine etc. but i dunno it could be C aswell...a weird one

14.A (I'm not sure about this one; my friend says C)

I got C anyways. im pretty sure that its right.

 

[Buiboi]

I thought they were pointing at xylem cells since a longtindual view of them show "double or single ring spirals of lignin". If you have the "Heinemann (second edition) Biology Activity Manual" Go to page 110 and they have the same diagram (labelled) that was given in the test...lucky for me i memorised it...But as i have stated before...saying whats right or wrong doesnt make a difference, BOS will show us the answers in 2 months...im probably wrong...who cares, just wait.

Goodluck People for your remainign exams.

yeah thats the diagram i saw! its the xylem

 

[Punksta07]

I liike you guys saying BOS will tell us the answer and we'll see whos right......you only get marks not how much you got in each section OR the specific answers for questions so really you will never know UNLESS someone gets 100% as a raw mark and you can ask them their answer =P


Oh and for 14 i put C simply because i was reading some ADH thing before the exam and i read that both were released but i couldn't remember why....seems like i made the right choice

Well since this is the "Multiple choice" forum and BOS does release answers for Multiple choice i do beleive we can find out which people had the right answers...its not a matter of someone obtaining 100% raw mark. I have already said i might be wrong so its best for all of us to wait until the MC answers have been released. If you have Henineman Biology, the answer for question 14 is there *check my previous posts for the page number*. Goodluck on your future exams and hope you all get the mark you wish to achieve