VCE Biology Question Thread

[vox nihili]

Is there only an immune response to one antigen or can multiple cells with different specificities be stimulated as a result of different antigens from the one pathogen?

It would seem to make sense that there is multiple but everyone always talks about one.

You’re quite right. It’s multiple.

[smamsmo22]

1. Monoclonal antibodies are identical antibodies that are produced by a single cell. The monoclonal antibodies are produced through injecting a mouse with specific antigens, it will then produce specific B plasma cells that synthesise antibodies against the injected antigens, whereby these B plasma cells can be extracted. Upon extraction, they are fused with myeloma cells (tumour plasma cells) from another mouse, forming a hybridoma. Hybridomas are immortal cell lines that produce unlimited amounts of the specific antibody concerned.

2. Correct. STOP codons do not code for any amino acids, only the START codon (methionine (AUG = Codon))

3. Umm.. not too sure what you are saying.. But exons are regions of DNA and mRNA that code for the specific polypeptide chain concerned, however introns are merely interruptions in that sequence.  (So, I guess you can use the terms exons AND introns to describe BOTH mRNA and DNA)

4. When describing the founder effect, a specific non-representative group of an original population (in terms of allele frequencies) colonises a new region (by chance), in which giving rise to a new population that has decreased genetic diversity (i.e. Huntington's Disease in Tasmania).

5. If you are asked a question about the pathway of cytokines (in terms of signal transduction) it will be identical to any other pathways that you would have already seen with other hormones (i.e. insulin etc.). Now in terms of the neurotransmitter, it depends. IS the neurotransmitter binding to a neuron in a neural pathway OR binding to an effector cell? If it is binding to a cell that is going to elicit a specific response, then the pathway is alike any 'general' signal transduction pathway, however, if it binding to another neuron then it binds to post-synaptic receptors that open and allow for the flow of ions... (i.e. sodium, chloride, etc).

6. In terms of including adenosine diphosphate and inorganic phosphate as reactants, I doubt it... you don't include NADP + H+ in photosynthesis (or do you? ha). If it asks for chemical; ATP is used.... if word, maybe say 'energy'.... often times they (VCAA) don't require any mention of 'energy'....

Ok thanks a lot!
 
So for monoclonal antibodies, the general idea of it is a plasma cell producing antibodies specific to the particular antigen or molecule that is to be targeted by the treatment (i.e. growth hormone receptors on cancer cells, other distinctive antigens on cancer cells) is extracted from an organism and fused with a myeloma/tumour cell which provides it with the ability to indefinitely divide. Then this hybrid cell is inserted into the infected person?

In earlier years of high school I'd always write the word equation as 'Glucose + oxygen -> ATP + carbon dioxide + water'. Is that ok, or is energy better than ATP? Thanks

[vox nihili]

Ok thanks a lot!
 
So for monoclonal antibodies, the general idea of it is a plasma cell producing antibodies specific to the particular antigen or molecule that is to be targeted by the treatment (i.e. growth hormone receptors on cancer cells, other distinctive antigens on cancer cells) is extracted from an organism and fused with a myeloma/tumour cell which provides it with the ability to indefinitely divide. Then this hybrid cell is inserted into the infected person?

In earlier years of high school I'd always write the word equation as 'Glucose + oxygen -> ATP + carbon dioxide + water'. Is that ok, or is energy better than ATP? Thanks

Nah you just use the hybrid cell to make the monoclonals in a dish. Then you insert the antibodies in the person.
The purpose of the hybrid cell is that you can grow it in a dish, whereas plasma cells can’t

ATP is fine

[smamsmo22]

Nah you just use the hybrid cell to make the monoclonals in a dish. Then you insert the antibodies in the person.
The purpose of the hybrid cell is that you can grow it in a dish, whereas plasma cells can’t

ATP is fine

Thankyou!

[skrt skrt]

Hi all, just a few questions I had during my studies.
1.How did Homo sapiens evolve out of Africa if homo erects was the first to migrate Africa?
2.Does anyone know of a template for experimental design(and construction of a hypothesis) , through past exams I've noticed this is my weakest point.

Thanks in advance for responses and good luck to all for exam.

[PhoenixxFire]

1. It's controversial, no one knows for sure, it's just one theory. (Just know the theories don't think about it too hard).
2. I don't know of any, it may be worth having a look at psychology resources as they have to do lots of experimental design.

[cookiedream]

Hi all, just a few questions I had during my studies.
1.How did Homo sapiens evolve out of Africa if homo erects was the first to migrate Africa?
2.Does anyone know of a template for experimental design(and construction of a hypothesis) , through past exams I've noticed this is my weakest point.

Thanks in advance for responses and good luck to all for exam.

1. As far as I know, the 'out of Africa' hypothesis suggests that H. erectus evolved in Africa and migrated to Europe, Asia and Indonesia. H. sapiens then evolved from H. erectus.

2. While this is no set format, it's a good guide so that you at least know where to start writing:

- Hypothesis
- Sample (number and characteristics. e.g. 100 plants of the same size, same species)
- Experimental and control group, where IV is clearly shown
- Controlled variables
- How DV is observed/measured
- What results would show that the hypothesis is supported?
- Repeat experiment several times

[TheBigC]

Hi all, just a few questions I had during my studies.
1.How did Homo sapiens evolve out of Africa if homo erects was the first to migrate Africa?
2.Does anyone know of a template for experimental design(and construction of a hypothesis) , through past exams I've noticed this is my weakest point.

Thanks in advance for responses and good luck to all for exam.

The previous comment addressed your second question quite well, so I will primarily address the first.

1.
- H. erectus migrated out of Africa. This is a known fact - in which you are clearly aware of... Now. It was not the ENTIRE species of H. erectus that migrated, only a select few populations (some scientists refer to these populations as H. ergaster).
- Now, the 'Out-of-Africa' hypothesis proposes that H. erectus evolved into H. sapiens and THEN H. sapiens migrated out of Africa (this is as much as VCAA wants you to be aware of)

[skrt skrt]

Thanks guys all your responses were great and helped alot. How are you guys preparing for the exam? I feel like i know all the content but the question will be asked in a way that will make me question myself.

[KANYEWEST]

Hey, were will i be able to get a copy of the answers to the VCE Biology practise exam for this year?

[PhoenixxFire]

If you mean the vcaa sample exam they are here: https://atarnotes.com/forum/index.php?topic=173234.0

[captkirk]

How many minutes should be spent on the multiple choice in the Biology exam. My teacher hasn't said anything about it.

[PhoenixxFire]

I would aim for 30min.

[cookiedream]

- H. erectus migrated out of Africa. This is a known fact - in which you are clearly aware of... Now. It was not the ENTIRE species of H. erectus that migrated, only a select few populations (some scientists refer to these populations as H. ergaster).
- Now, the 'Out-of-Africa' hypothesis proposes that H. erectus evolved into H. sapiens and THEN H. sapiens migrated out of Africa (this is as much as VCAA wants you to be aware of)

Wait, so to clarify:
- Some H. erectus populations did migrate out of Africa
- The H. erectus populations which did not migrate in Africa were the populations from which H. sapiens evolved and migrated to Europe, Asia, etc hence are the ones involved in the Out of Africa hypothesis?

How does this relate to the fact that no African populations have any Neanderthal DNA?

[Jackie Chan]

Wait, so to clarify:
- Some H. erectus populations did migrate out of Africa
- The H. erectus populations which did not migrate in Africa were the populations from which H. sapiens evolved and migrated to Europe, Asia, etc hence are the ones involved in the Out of Africa hypothesis?

How does this relate to the fact that no African populations have any Neanderthal DNA?

Modern day Africans don't have any Neanderthal DNA as the hominin population that remained in Africa and did not migrate, were unable to cross paths with other hominins such as Homo Neanderthalensis and therefore could not interbreed with them. Other races of modern humans would have Neanderthal DNA as the Homo sapiens that did migrate out of Africa had interbred with Homo neanderthalensis.

EDIT: Neanderthal ancestors had left Africa before Homo sapiens evolved according to a STAV paper.
Someone please correct me because I'm not 100 percent certain.