my multiple choice answers (2 Viewers)

[ari89]

For the 8 marker question, when people say they talked about Koch's Postulates, I wrote that down as a plan, but later not to include it in, as Koch Postulates refers to INFECTIOUS DISEASES only. I know, how they mentioned that he swallowed it and all, but i think, that was a trick? Anyway, that question was stupid.

Nah it wasn't a trick and you were suppose to refer to Koch's postulates as the question asked about their method in identifying the pathogen as the cause for a particular disease. A pathogen is an infectious disease (remember the dot point where you have to describe under what conditions a microorganism is a pathogen?)- pathogens must be able to survive transfer from one host to another.

However, I thought it was a really stupid question and I also was expecting it to either be on transgenic species and the effect on natural populations OR evaluating vaccination programs such as with smallpox, diptheria and polio. But I am glad it wasn't on those because the question was relatively simple to write about.

Hope everyone did well

 

[Helplessness]

what was up with mc Q10?? i put down kidney...THERE WAS NOTHING ESLE ON THERE THAT WAS ON THE FREAKIN SYLLABUS!!!!! HOW CRAP!

 

[ari89]

what was up with mc Q10?? i put down kidney...THERE WAS NOTHING ESLE ON THERE THAT WAS ON THE FREAKIN SYLLABUS!!!!! HOW CRAP!

It was a syllabus dot point for maintaining a balance...

describe the main changes in the chemical composition of the blood as it moves around the body and identify tissues in which these changes occur

However I myself wasn't prepared for it either but assumed it from the preliminary course where we looked at the digestive system in mammals and how in the small intestines nutrients is absorbed by microvilli into the blood stream or something like that...

 

[Helplessness]

that's crap, there goes one mark down the drain...i also didn't refer to koch's postulates but i definitely wrote about validity and accuracy which is more important than koch's postulates....

 

[Dr_Doom]

All I did was rewrite in koch's posulates and add a sentence on the end.

eg/

3rd step) The guy ate the bacteria.blah blahb lah.. This showed that the bacteria caused the infection.

 

[ari89]

that's crap, there goes one mark down the drain...i also didn't refer to koch's postulates but i definitely wrote about validity and accuracy which is more important than koch's postulates....

I thort the crux of the question was the validity that was associated with using koch's postulates which has been a widely accepted method for determining whether or not a pathogen was the cause of a particular disease, since the ideas conception in the late 19th century or whatever...
What did you write to talk about accuracy?

 

[Survivor39]

The 8 mark question appears to be very interesting based on the discussion here (not exactly sure what they asked).

Did they mention Marshall and Warren and their Nobel prize for demonstrating Helicobacter pylori as the cause of stomach ulcers or something?

Marshall was trying to demonstrate that H. pylori was the casative agent for stomach ulcer but he couldn't fulfil the third Koch's postulate using animal models. So he drank the bug to show that bacteria isolated from the ulcers could cause ulcers in humans.

 

[suchet_i]

i wrote down in which they didnt perform the last step of koch postulate - the after infecting an healthy organism you should extract the same pathogen from him

 

[ari89]

The 8 mark question appears to be very interesting based on the discussion here (not exactly sure what they asked).

Did they mention Marshall and Warren and their Nobel prize for demonstrating Helicobacter pylori as the cause of stomach ulcers or something?

Marshall was trying to demonstrate that H. pylori was the casative agent for stomach ulcer but he couldn't fulfil the third Koch's postulate using animal models. So he drank the bug to show that bacteria isolated from the ulcers could cause ulcers in humans.

They gave us an exert from a source (The Australian Magazine or sumfin for December 2005) and it talked about how Marshall and Warren won a nobel prize for demonstrating that they found the bacterium responsible for causing stomach ulcers and gastritis which were previously believed to be caused by stress and poor diet. Then they had a quote from one of the guys saying that 'they told us that bacteria couldn't grow in the acidic environment of the stomach but we found it...'

Then out of the source there was info which listed their methodology of identifying Helicobacter pylori as the pathogen responsible for ulcers and gastritis:
- They used prepared slides of ulcer tissue
- They used flexible endoscopes to identify swelling in the stomach
- They utilised staining methods to identify the presence of the bacterium in the tissue
- Something else here i think...

Then they told us that Marshall was tested for the presence of H. pylori and it was negative. So, he swallowed the bacterium and showed symptoms of gastritis.

And the actual question was:

Discuss the methodology used by Marshall and Warren to identify the pathogen as being the cause of stomach ulcers and gastritis. (or something along those lines)

 

[Dr_Doom]

i wrote down in which they didnt perform the last step of koch postulate - the after infecting an healthy organism you should extract the same pathogen from him

Yeah I wrote that down aswell. But I said since they already knew what they were inserting in him and he showed the same symptoms, then that proves it was the causative pathogen.....

The 8 mark question appears to be very interesting based on the discussion here (not exactly sure what they asked).

Did they mention Marshall and Warren and their Nobel prize for demonstrating Helicobacter pylori as the cause of stomach ulcers or something?

Marshall was trying to demonstrate that H. pylori was the casative agent for stomach ulcer but he couldn't fulfil the third Koch's postulate using animal models. So he drank the bug to show that bacteria isolated from the ulcers could cause ulcers in humans.

Yeh it said all that. Then it went and described things they did that were related to Koch's Posulates. They weren't in order either which might have confused some people.

 

[angmor]

u can talk about koch's postulates and relate them to their methods. i thought that their method wasnt that good since when they implanted the bacteria in Marshall, they did not attempt to isolate the organism from him.

however i also talked about how antibiotic use could be one way to determine if the bacterium is the cause of the ulcers

 

[cclift]

all the same as u cept i got D for 5 because although both C and D could have produced this result, D is more likely bcoz its the monohybrid ratio

Sorry but its C, a homozygous cross could not possibly produce both pure dominant and recessive genotypes..
I screwed 9 and 15 I think you got all right.. wd!

 

[ari89]

Sorry but its C, a homozygous cross could not possibly produce both pure dominant and recessive genotypes..
I screwed 9 and 15 I think you got all right.. wd!

I agree with you!

Homozygous pair cross --

T T
t Tt Tt
t Tt Tt

Heterozygous pairs ---

T t
T Tt Tt
t Tt tt

See the difference? Heterozygous pairs show the mendelian ratio of 3:1

 

[ali777]

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

I got all the same except 10...i chose B, the kidney. i was leaning towards D cos the digestive products would come from the small intestine...but does blood pass throughthe small intestine?? i know id be pretty concerned if i found blood in there...haha but anyway, was this question meant to be interpreted literally, or were we just meant to recognise that blood passed around the small intestine & carried digestive products & carbon dioxide away?? i dont know. oh well, i was happy with the rest of my answers.

 

[kido_1]

was 10 b or was 10 d.
I put d wat about you.
There were some tricky questions but overall the exam was really fine.

 

[pirate!]

Bloody Human Story option. Mitochondrial DNA and I don't mix well at the best of times. but a 6 mark question?! Why do they have to be so evil?! I swear, we did about...oh, 20 minutes or so on it in class - max. evil evil bastards.

Yucky kidney and ADH and aldosterone questions. I just suck at them in general, so I wasn't very happy.

 

[4DOGS]

I thought the 8 mark question was more about validity and that crap because the key word they used was 'assess' not 'describe'. anyone else agree?

 

[bugger69kr]

I agree with you!

Homozygous pair cross --

T T
t Tt Tt
t Tt Tt

Heterozygous pairs ---

T t
T Tt Tt
t Tt tt

See the difference? Heterozygous pairs show the mendelian ratio of 3:1

Dude you got it wrong.
T t
T TT Tt
t Tt tt

Heterozygous pairs show the medelian ratio 1:2:1

But anyway you got the answer right ! i got 4 multiple choice questions wrong and 3 of them were changed in the last min....ARGH it kills

 

[wytcpl]

The 8 marker asked to assess the procedures and conclusions.

You can determine validity by examining how closely they adhere to appropriate methodology. In this case, the appropriate methodology was Koch's postulates.

1. The animals with the disease must be shown to have the suspected pathogen.
Acoording to the information given, they didn't do this. All they did was examine slides and live tissue, and proved that there was possibly bacteria through staining (they didn't even say what type of bacteria)

Steps 2 and 3 were fine.

4. The pathogen must be reisolated from the experimentally infected animal.
They didn't reisolate the Helicobacter.

So their conclusions were based on the incomplete adherence to Koch's postulates. Therefore, based on available information, their conclusions were invalid.

Also, their procedures were dangerous; one should not ingest pathogens that have an unknown or suspected dangerous result. Their procedures were dangerous and irresponsible.

I know that they won a Nobel prize which probably means that they obviously did prove beyond doubt that the Helicobacter caused the disease, but based on the information provided, their procedure was dangerous and their results were invalid, or inconclusive at best.

 

[viva_la_emma]

My experiment design for the water saving structure was so dodgy though, all I could think of was putting the plants, and other similar plants without the structure in containers with gladwrap over the top and then comparing the amount of precipitation on the top for each plant. I hope it atleast makes the marker chuckle. Lame.
.

that was my experiment idea too. i think its pretty ok for straight off the top of the head. =) so they can chuckle at both of ours

i thought it was ok. but they never give you enough lines to write and wen i fil the lines and read over im like that is not worth 4 marks so i write so much extra crap

my option

biochemistry - not fun... they asked the randomest things that we never learnt properly. i only learnt bio the night before! hahah

but i rambled on so yay me. lol