VCE Biology Question Thread

[plsbegentle]

do we need to know other plant hormones beside auxin?

[The Usual Student]

do we need to know other plant hormones beside auxin?

not really, at least from my knowledge

[Vaike]

Monoclonal antibodies are a relatively new technology that is taking world of pharmaceuticals by storm. Used as treatments for a number of conditions, monoclonal antibodies are antibodies that show specificity for human molecules.

An example of a monoclonal antibody is dupilumab, which is specific to the IL-4 receptor chain alpha. IL-4 receptor chain alpha is a protein segment found in both the IL-4 and IL-13 receptors. These receptors are activated by the cytokines IL-4 and IL-13 respectively. Dupilumab is used in the treatment of asthma.


1. Explain why dupilumab might be useful in asthma.
2. Suggest a way that monoclonal antibodies could be made.

1. -The symptoms of asthma are caused in part by the binding of cytokines IL-4 and IL-13 to their respective receptors.
-Dupilumab is able to bind to the IL4-receptor chain alpha, which is found in both of the aforementioned receptors.
-The binding action of Dupilumab to these protein chain alters the binding site of these receptors, resulting in the cytokines being unable to bind to their receptors, and thus the introduction of these monoclonal antibodies into the body may lessen the symptoms of asthma.

2. Monoclonal antibodies against the IL-4 protein chain alpha may be produced by injecting these proteins into a non human organism, such as mice. In doing so, the protein fragments would be recognised as non self in the organism they were introduced into. Thus, specific antibodies would be produced against it in large numbers. These antibodies could then be extracted and then be refined for human use.   

I have no idea how relevant/accurate any of this is, but I tried to answer this as I would a VCAA question, I have found the answer to their questions are usually simple and relatively uncomplicated, which is what I tried to do here

[Gogo14]

Not a bad crack at it, but for #1 in particular maybe reread the question. You're giving dupilumab's mechanism of action—why is this relevant to asthma?
Your answer to number two is interesting. It's not what I was looking for, but it's relevant to some of the more advance details of how these are made, which is interesting. In any case...here's a hint. What would happen if a mouse antigen got in a human?

Ok here's another shot
1. Dupilumab has complementary binding sites to IL-4, which is a cytokine, presumably histamine. As a result of binding to this cytokine, the antibody inhibits its function by agglutination of IL-4 hence preventing circulation of the cytokine around the body. As a result, allergic side effects like inflammation and swelling is decreased.
2. Genes for Production of human antibodies are inserted into another animal via a recombinant plasmid. The animal then produces this monoclonal antibody and the antibodies are collected for use.
Not sure if half of what I said was relevant, Lol

[lasagne]

Monoclonal antibodies are a relatively new technology that is taking world of pharmaceuticals by storm. Used as treatments for a number of conditions, monoclonal antibodies are antibodies that show specificity for human molecules.

An example of a monoclonal antibody is dupilumab, which is specific to the IL-4 receptor chain alpha. IL-4 receptor chain alpha is a protein segment found in both the IL-4 and IL-13 receptors. These receptors are activated by the cytokines IL-4 and IL-13 respectively. Dupilumab is used in the treatment of asthma.

1. Explain why dupilumab might be useful in asthma.
2. Suggest a way that monoclonal antibodies could be made.

Not sure any of this actually says anything, but yeah
1. Dupilumab acts as a competitive inhibitor to the cytokines IL-4 and IL-3, binding to the IL-4 and IL-3 receptors. Thus, the binding of these cytokines is decreased and therefore the effects of asthma are also decreased.
2. Mice are injected with the antigens and produce antibodies against it. The plasma cells are taken from the mice and mixed with tumour cells to create hybridomas. The hybridoma cells that make the desired antibody are then cultured to produce large amounts of it.

[AhNeon]

If a person is screened to have an autoimmune disease, but does not show any autoantibodies in their blood to indicate the disease, is it possible that the specific lymphocytes against the self-tissue have just not yet come into contact with the self-antigen?

[HasibA]

If a person is screened to have an autoimmune disease, but does not show any autoantibodies in their blood to indicate the disease, is it possible that the specific lymphocytes against the self-tissue have just not yet come into contact with the self-antigen?

id think so. but then- aren't autoantibodies always present if a individual has an autoimmune disease, and  very likely not visible if they dont have it? did that make sense (sorry ;P) ahah

[Hopelesshopefull]

If a person is screened to have an autoimmune disease, but does not show any autoantibodies in their blood to indicate the disease, is it possible that the specific lymphocytes against the self-tissue have just not yet come into contact with the self-antigen?

could just be a false positive test result

[sweetcheeks]

If a person is screened to have an autoimmune disease, but does not show any autoantibodies in their blood to indicate the disease, is it possible that the specific lymphocytes against the self-tissue have just not yet come into contact with the self-antigen?

The gene may not have been activated yet.

[anniebrejcha]

just double checking; but is competitive and non-competitive enzyme inhibition temporary?


edit: wait sorry asking only about non-competitive inhibition. i understand that competitive inhibition can be reversed.

[AhNeon]

Could someone confirm im not buckling and the answer for this is A? The answers are saying B but ive done it like 5 times and only gotten A

[sweetcheeks]

Could someone confirm im not buckling and the answer for this is A? The answers are saying B but ive done it like 5 times and only gotten A

When I did it I achieved b.
A cross between a hh ww individual and Hh Ww should result in the following genetypes;
HhWw- Yellow + Hair
Hhww- White and hair
hhWw- Yellow no hair
hhww- white no har

[The Usual Student]

just double checking; but is competitive and non-competitive enzyme inhibition temporary?


edit: wait sorry asking only about non-competitive inhibition. i understand that competitive inhibition can be reversed.

Yeah non-competitive is usually permanent but I found some examples that are not. I think it is an ok assumption to just say the majority of them are permanent.

[hodang]

Why are memory cells short lived?

[AhNeon]

When I did it I achieved b.
A cross between a hh ww individual and Hh Ww should result in the following genetypes;
HhWw- Yellow + Hair
Hhww- White and hair
hhWw- Yellow no hair
hhww- white no har

But that doesnt really include the ratios of which the genotypes/phenotypes will show up in
If you account for that, 12/16 wouldd have the H allele so wouldnt A make sense?