Multiple Choice (3 Viewers)

[Buiboi]

also i'm pretty sure with 14 it's A... i origionally had C until i changed it.. and there are lots of different answers here.. BUT i think a because if he had a low blood pressure then both would be released and aldosterone is only to either raise the blood pressure or rasie the salt ions in the body.. and the question is not asking for any of that it is simply saying the marathon runner is dehydrated- meaning the cells do not have enough water, the water balance is out. This would mean there is already too much salt.. so no more salt is needed.
thats my take...

ADH is responsible for increasing the permeablity of the collecting ducts of the nephron in absorbing water..so ADH increases for sure

aldosterone increases the reabsorption of salts, hwoever, salts as in the absoroption of sodium ions and getting rid of potassium, and sodium ions is responsible for water retention. so if he was to dehydrate, he would need to have an increase in aldosterone to retain the water he currently has and increase water concentrations with more adh, so they work hand in hand, also addisons disease is the disruption of the adrenal cortex, which means not enough aldosterone is produced and a consequence of the addisons disease is severe dehydration so.... yeah thast what i believe

 

[k4t5UM0t0]

1. D (substrate is the reactant)
2. B (it just is)
3. A (its not a phloem so its xylem)
4. C (prevent it from entering area)
5. B (dependent variable is the one which is measured)
6. B (it just is)
7. D (it just is)
8. D (Koch's observation was which pathogen caused a disease Kochs
Postulates)
9. D (Pea plants pollinate and he did not clone them)
10. A (it just is)
11. B (From Family 2 it is deducable that it is recessive. The trait is not sex-linked
and the two parents are heterozygous and hence 25%)
12. A (T-cells recognise antigen first before B-cells stimulate, they don't occur at
same time)
13. C (Populations can't adapt to insecticide if they are already dead)
14. C (ADH increases premeability in kidneys increasing water reabsorption and
aldosterone also increases water reabsorption, the runner is dehydrated
so by homeostasis he's going to increase water reabsorption)
15. D (it just is)

 

[yoakim]

1. D - I believe the substrate is the reactant, not the product.
2. B
3. A - The rings are characteristic of xylem vessels, and xylem transports water and mineral ions.
4. C - Prevention is better than cure.
5. B - The treatment is the independant variable. The number of visible bacterial colonies depends on that variable, and is thus the dependant variable.
6. B
7. D
8. D
9. D
10.A
11.B
12.A
13.C
14.A (I'm not sure about this one; my friend says C)
15.D

Yeah that's exactly what I had. Except I stupidly chose 0% for Q.11. Q.14 is C.

 

[joshuaali]

yes I agree with you.

question 1 is A

because isn't A and B the enxyme with the active site... and then the object C is the substrate...

Enzymes are biological catalysts. Catalysts lower the activation energy of the reaction but are present in the same condition before and after the reaction (i.e. they are not used up in the reaction or changed or anything).

In the diagrams, the only change from the start and finish is the bonding of A and B, thus they must be the substrate and C must be the enzyme (since it is not changed at all).

 

[wangurflapper88]

also i'm pretty sure with 14 it's A... i origionally had C until i changed it.. and there are lots of different answers here.. BUT i think a because if he had a low blood pressure then both would be released and aldosterone is only to either raise the blood pressure or rasie the salt ions in the body.. and the question is not asking for any of that it is simply saying the marathon runner is dehydrated- meaning the cells do not have enough water, the water balance is out. This would mean there is already too much salt.. so no more salt is needed.
thats my take...

with the reabsorption of salt aldosterone allows for water to follow it passively helping to restore the water balance also.

 

[roosterman57]

Heh. For 11, I think it's B since, after analysing the diagram, you can see that the 'affected' allele is recessive to the 'normal' allele (and they aren't sex-linked). From just that fact, you can see that A and B must be heterozygous to have an 'affected' son. Thus, in a true mendelian ratio, the chances of the daughter having a recessive phenotype must be a 1/4, i.e. 25%.

I think ur right. i did punnet squares but for some stupid reason i did sex linked punnet squared cross XX and XY. I dont know why. I just realised :S

 

[yoakim]

yes I agree with you.

question 1 is A

because isn't A and B the enxyme with the active site... and then the object C is the substrate...

An enzyme does not get used or nor change its structure when catalysing a reaction. Hence C is the substance of an enzyme. C is the product formed when 2 substrate parts join together due to the catalysed reaction. D is the substrate which is its 2 forms.

 

[starrysky]

I think ur right. i did punnet squares but for some stupid reason i did sex linked punnet squared cross XX and XY. I dont know why. I just realised :S

Ditto. I put B for Question 11 - happy about that.

MC was fairly straightforward - I liked it.

 

[Emchem]

Enzymes are biological catalysts. Catalysts lower the activation energy of the reaction but are present in the same condition before and after the reaction (i.e. they are not used up in the reaction or changed or anything).

In the diagrams, the only change from the start and finish is the bonding of A and B, thus they must be the substrate and C must be the enzyme (since it is not changed at all).

ahhhhhh yep that makes sense now...sweeet!!!

3 wrong I think...which isn't too bad or too great

 

[Buiboi]

man how is one A!!!?!?
i got fooled the first time. thought itwas the combined blocks.

enzymes dont change in reactions!?!?

block AB (C) is the product produced
and d =substrate

 

[Emchem]

what is the verdict for q14

I put, c that both ADH and aldosterone are released...? is this correct?

 

[Rachael21]

Yay, I got pretty much the same as everyone else...

1. D
2. B
3. A
4. C
5. B
6. B
7. D
8. D
9. D
10. A
11. B
12. A
13. C
14. C
15. D

I thought the multiple choice was pretty easy. I just hope I payed attention and didn't colour in the wrong circles

 

[roosterman57]

what is the verdict for q14

I put, c that both ADH and aldosterone are released...? is this correct?

have u not read this whole thing yet? lol

 

[xxJTxx]

1. D (substrate is the reactant)
2. B (it just is)
3. A (its not a phloem so its xylem)
4. C (prevent it from entering area)
5. B (dependent variable is the one which is measured)
6. B (it just is)
7. D (it just is)
8. D (Koch's observation was which pathogen caused a disease Kochs
Postulates)
9. D (Pea plants pollinate and he did not clone them)
10. A (it just is)
11. B (From Family 2 it is deducable that it is recessive. The trait is not sex-linked
and the two parents are heterozygous and hence 25%)
12. A (T-cells recognise antigen first before B-cells stimulate, they don't occur at
same time)
13. C (Populations can't adapt to insecticide if they are already dead)
14. C (ADH increases premeability in kidneys increasing water reabsorption and
aldosterone also increases water reabsorption, the runner is dehydrated
so by homeostasis he's going to increase water reabsorption)
15. D (it just is)

Uhhh mostly the same for me..same reasoning for the ones that were anyway.
11 threw me, silly mistake..oh well. I'm over it haha. I stupidly put A having not examined the silly pedigree well enough, and think omg they didn't say if the trait was recessive/sex linked or whatever...AH! I'm upset bout this one.

14 I put A. I was trying to decide between A and C, but then I thought...the runner's body is dehydrated i.e. body screming "I NEED WATER" so ADH will definitely be released. But why not aldosterone? Umm I guess I thought if its the response this could have happened because water passively follows when the salt is actively reabsorbed, but the scenario just give enough about the situation to deduce that. Why would he want salt as well? I dunnoz.

Other then that, short answer was pretty much straightforward that stupid one with the bases and their percentages made me fill stupid. And I hated the 8 marker, out of all the things that put a lame one.

 

[hoca pontis]

oh no!!!!
for Q10, i knew it was A...but for some weird reason, i put B!! oh man, that sucks...

 

[2opinion8d]

1. D - I believe the substrate is the reactant, not the product.
2. B
3. A - The rings are characteristic of xylem vessels, and xylem transports water and mineral ions.
4. C - Prevention is better than cure.
5. B - The treatment is the independant variable. The number of visible bacterial colonies depends on that variable, and is thus the dependant variable.
6. B
7. D
8. D
9. D
10.A
11.B
12.A
13.C
14.A (I'm not sure about this one; my friend says C)
15.D

yay! same answers....

how would u guys justify the Wollemi Pine question... i thought having the scientists washing their shoes would be the best preventative measure because i assumed that the fungus could be present around australia since "the last small population grows in a remote national park in NSW"

my friends said they put D (preventing the importation of infected Wollemi pines into Australia)

 

[gaj]

what is the verdict for q14

I put, c that both ADH and aldosterone are released...? is this correct?

I put C because the body is dehydrate, which means it needs water and the blood pressure is low. ADH is released to make the permeability of the membrane higher to allow more water reabsorbtion, and aldostyerone is released to increase bp.

 

[kobina]

hey
q14 does say that the body was dehydrated
it sed nothing about "sweating" (salt loss) in paticular. this alludes that the ansa has to b A) because

ADH acts to retain water
aldosterone onli works on salt

maybe in a pdh exam the answer could be c

 

[gaj]

yay! same answers....

how would u guys justify the Wollemi Pine question... i thought having the scientists washing their shoes would be the best preventative measure because i assumed that the fungus could be present around australia since "the last small population grows in a remote national park in NSW"

my friends said they put D (preventing the importation of infected Wollemi pines into Australia)

d is definately wrong because the wollemi pines are already in australia and the answer is definately C baecause you are trying to prevent the spread of the fungus to the small population of pines. the others dont prevent anything

 

[gaj]

hey
q14 does say that the body was dehydrated
it sed nothing about "sweating" (salt loss) in paticular. this alludes that the ansa has to b A) because

ADH acts to retain water
aldosterone onli works on salt

maybe in a pdh exam the answer could be c

the person just ran a marathon, im pretty sure their is no one that doesn't sweat after running a marathon. it is true that aldosterone acts on increaseing sodium reabsorbtion, but this is too maintain blood pressure. someone who is dehydrated will hjave low bp and the increased reabsorbtion of sodium causes an increase in water osmosi, thus increaseing bp