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July 19, 2025, 12:05:29 pm

Author Topic: Biology Unit 3 Questions Megathread  (Read 116956 times)  Share 

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WhoTookMyUsername

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Re: Biology Questions Megathread
« Reply #540 on: May 28, 2011, 12:53:33 pm »
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Maybe i should just put 'thanks Russ and all answers in bio q megathread '

1 more question 


i am confused as to the terms adenovirus, retrovirus etc.

i know adenovirus have dna
retrovirus have rna

but i don't think all rna / dna are retro/adeno

so what is the difference and how do you tell?

EDIT: Do all bacteriophages have DNA or do some have RNA

Russ

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Re: Biology Questions Megathread
« Reply #541 on: May 28, 2011, 01:18:04 pm »
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i don't entirely agree with this answer, I went with c.

It does require you to know something about Thyroxine, so I guess it's not the best question. A quick glance at the thyroxine structure should indicate that it's pretty non polar (two aromatic rings...). As such A is correct but the only way to know it is by knowing the structure. As well as that, in the question they state that it binds target cell receptors which is probably also true so...bad question.

Quote
Maybe i should just put 'thanks Russ and all answers in bio q megathread '

I'm majoring in microbiology and immunology, this section of the course is fun revision for me :P

Quote
but i don't think all rna / dna are retro/adeno

so what is the difference and how do you tell?

There are a ton of taxonomic families (retroviridae etc.) and the only way to know whether or not it's DNA/RNA is to be told by your teacher. You don't need to know why or how they're categorized for VCE. Retroviruses, however, are also defined by the ability to convert RNA to DNA and integrate it back into the host genome (i've said this before in this thread, it breaks the crick central dogma)

Quote
Do all bacteriophages have DNA or do some have RNA

Either.

WhoTookMyUsername

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Re: Biology Questions Megathread
« Reply #542 on: May 28, 2011, 02:05:19 pm »
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i don't entirely agree with this answer, I went with c.

It does require you to know something about Thyroxine, so I guess it's not the best question. A quick glance at the thyroxine structure should indicate that it's pretty non polar (two aromatic rings...). As such A is correct but the only way to know it is by knowing the structure. As well as that, in the question they state that it binds target cell receptors which is probably also true so...bad question.

Quote
Maybe i should just put 'thanks Russ and all answers in bio q megathread '

I'm majoring in microbiology and immunology, this section of the course is fun revision for me :P

Quote
but i don't think all rna / dna are retro/adeno

so what is the difference and how do you tell?

There are a ton of taxonomic families (retroviridae etc.) and the only way to know whether or not it's DNA/RNA is to be told by your teacher. You don't need to know why or how they're categorized for VCE. Retroviruses, however, are also defined by the ability to convert RNA to DNA and integrate it back into the host genome (i've said this before in this thread, it breaks the crick central dogma)

Quote
Do all bacteriophages have DNA or do some have RNA

Either.

Thanks again :)
i thought all amino acids had to go through protein channels / cell membrane / hydrophilic?? due to carboxyl??


quick search on line indicates all thyroid hormones are lipophilic ?

what are hydrophilic amino acid derivitative hormones/?

« Last Edit: May 28, 2011, 02:14:46 pm by Bazza16 »

Kaille

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Re: Biology Questions Megathread
« Reply #543 on: May 28, 2011, 04:05:47 pm »
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i don't entirely agree with this answer, I went with c.

It does require you to know something about Thyroxine, so I guess it's not the best question. A quick glance at the thyroxine structure should indicate that it's pretty non polar (two aromatic rings...). As such A is correct but the only way to know it is by knowing the structure. As well as that, in the question they state that it binds target cell receptors which is probably also true so...bad question.

Quote
Maybe i should just put 'thanks Russ and all answers in bio q megathread '

I'm majoring in microbiology and immunology, this section of the course is fun revision for me :P

Quote
but i don't think all rna / dna are retro/adeno

so what is the difference and how do you tell?

There are a ton of taxonomic families (retroviridae etc.) and the only way to know whether or not it's DNA/RNA is to be told by your teacher. You don't need to know why or how they're categorized for VCE. Retroviruses, however, are also defined by the ability to convert RNA to DNA and integrate it back into the host genome (i've said this before in this thread, it breaks the crick central dogma)

Quote
Do all bacteriophages have DNA or do some have RNA

Either.

Thanks again :)
i thought all amino acids had to go through protein channels / cell membrane / hydrophilic?? due to carboxyl??


quick search on line indicates all thyroid hormones are lipophilic ?

what are hydrophilic amino acid derivitative hormones/?



Thanks russ

Ohmygosh i never knew why amino acids had to go through protein channels before you told they had a carboxyl group !! thanks bazza16 :)

Hydrophilic Amino acid derivative hormones are derived from amino acids. They leave cells via diffusion exocytosis and have a short life span and they tral in the blood stream. Hydrophilic refers to its inability to cross the cell membrane as it is water soluble, however there are some exceptions, such as thyroxine.
B.Biomed, Melbourne 2013-

Kaille

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Re: Biology Questions Megathread
« Reply #544 on: May 28, 2011, 04:28:27 pm »
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Also, am i right in saying that a retrovirus has RNA as its genetic material which produces viral DNA from viral RNA. This DNA is then integrated into the host's chromasomes which causes a change in gene transcription?
B.Biomed, Melbourne 2013-

WhoTookMyUsername

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Re: Biology Questions Megathread
« Reply #545 on: May 28, 2011, 05:09:45 pm »
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What type of phagocytic cells can eat cells infected by viruses?

lexitu

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Re: Biology Questions Megathread
« Reply #546 on: May 28, 2011, 05:28:06 pm »
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What type of phagocytic cells can eat cells infected by viruses?


None I'm pretty sure..? Or at least the main mechanism is Cytotoxic T cell destruction.

WhoTookMyUsername

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Re: Biology Questions Megathread
« Reply #547 on: May 28, 2011, 05:33:40 pm »
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m... my teacher and a few videos said some macrophages ingest whole virus infected cells, but i couldn't find any examples of this,
i think your right, can anyone confirm?
thanks lexitu

jane1234

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Re: Biology Questions Megathread
« Reply #548 on: May 28, 2011, 05:56:47 pm »
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With experimental design involving a group of humans, would you want a mix of age, ethnicity, weight etc or all those factors kept the same? Otherwise the result might just be the effect of the age group etc?

lexitu

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Re: Biology Questions Megathread
« Reply #549 on: May 28, 2011, 06:02:05 pm »
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You don't really need to be that specific - it would depend entirely on the type of experiment. Oftentimes the group is kept very similar - e.g. healthy caucasian males between 25-30. The main thing is to acknowledge that you are controlling these factors.

Kaille

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Re: Biology Questions Megathread
« Reply #550 on: May 28, 2011, 11:03:35 pm »
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I don't agree with this answer either. if ribosomes are membrane bound, why are they found in bacteria?

Unless they mean attached to endoplasmic reticulum...

Cells are involved in the production of many different biomacromolecules, many of which must be packaged and transported out of the cell. Polypeptides that require such transport are synthesised by
A. the smooth endoplasmic reticulum.
B. the Golgi apparatus.
C. free ribosomes found in the cytosol.
D. membrane-bound ribosomes.

D is the answer
B.Biomed, Melbourne 2013-

Truck

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Re: Biology Questions Megathread
« Reply #551 on: May 28, 2011, 11:20:50 pm »
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I don't agree with this answer either. if ribosomes are membrane bound, why are they found in bacteria?

Unless they mean attached to endoplasmic reticulum...

Cells are involved in the production of many different biomacromolecules, many of which must be packaged and transported out of the cell. Polypeptides that require such transport are synthesised by
A. the smooth endoplasmic reticulum.
B. the Golgi apparatus.
C. free ribosomes found in the cytosol.
D. membrane-bound ribosomes.

D is the answer

The ribosomes on the rough endoplasmic reticulum are membrane-bound, but there are ones that are found in the cytosol as well, hence why they're in prokaryotic cells.
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Kaille

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Re: Biology Questions Megathread
« Reply #552 on: May 29, 2011, 10:25:30 am »
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I don't agree with this answer either. if ribosomes are membrane bound, why are they found in bacteria?

Unless they mean attached to endoplasmic reticulum...

Cells are involved in the production of many different biomacromolecules, many of which must be packaged and transported out of the cell. Polypeptides that require such transport are synthesised by
A. the smooth endoplasmic reticulum.
B. the Golgi apparatus.
C. free ribosomes found in the cytosol.
D. membrane-bound ribosomes.

D is the answer

The ribosomes on the rough endoplasmic reticulum are membrane-bound, but there are ones that are found in the cytosol as well, hence why they're in prokaryotic cells.

so you're saying that the ribosomes found in the cytosol are not membrane bound?
B.Biomed, Melbourne 2013-

WhoTookMyUsername

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Re: Biology Questions Megathread
« Reply #553 on: May 29, 2011, 11:00:22 am »
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can anyone confirm whether macrophages can / cannot ingest whole virus infected cells? or is it just Tc / NK that kill viruses ?


Also
My textbook says that Th cells are 100% neccessary to stimulate ploliferation of B cells, but it also says T cells can only detect antigens on antigen presenting cells,

Does this mean that lone antigens / pathogens cannot cause B cells to ploliferate ?


EDIT:
Immunity is confusing me!





another 2 questions


1) exactly  how are viruses destroyed and completely eradicated from body, is it by forming antibody virus complexes or by NK / Tc cells stopping them from reproducing or both

2) B cell has a similar (exactly the same) T cell, does this mean if an antigen binds with a B cell, they have to present this to the one correct Th cell and then the Th cell instructs the B cell to proliferate?

lexitu

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Re: Biology Questions Megathread
« Reply #554 on: May 29, 2011, 11:47:35 am »
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I don't agree with this answer either. if ribosomes are membrane bound, why are they found in bacteria?

Unless they mean attached to endoplasmic reticulum...

Cells are involved in the production of many different biomacromolecules, many of which must be packaged and transported out of the cell. Polypeptides that require such transport are synthesised by
A. the smooth endoplasmic reticulum.
B. the Golgi apparatus.
C. free ribosomes found in the cytosol.
D. membrane-bound ribosomes.

D is the answer

The ribosomes on the rough endoplasmic reticulum are membrane-bound, but there are ones that are found in the cytosol as well, hence why they're in prokaryotic cells.

so you're saying that the ribosomes found in the cytosol are not membrane bound?

Yeah, they're not membrane bound. Even the ones found at rough endoplasmic reticula aren't exactly membrane-bound: http://en.wikipedia.org/wiki/Ribosome#Membrane-bound_ribosomes.