VCE Biology Question Thread

[AllG_]

Currently human insulin used by diabetics is mainly produced by bacteria into which the gene for human insulin production has been inserted. Which of the following terms identifies the insertion process?

A. Gene splicing
B. Mutation
C. Crossing over
D. Transformation.

The chose D. The correct answer is A.

Can someone please explain to me how this is not an example of transformation?

Also for the question attached I choose D but the the correct answer is B. I thought the internal environment of multicellular organisms was the blood plasma and interstitial fluid, and that the extracellular fluid different to the interstitial fluid?
So I was confused with this question.

Clarifications would be great!

For the second question, the internal environment refers to the extracellular fluid in which body cells of multicullular organisms are bathed in. The extracellular fluid is the collective term for interstitial fluid and blood plasma so you are correct in saying that the internal environment comprises of interstitial fluid and plasma but yeah extracellular fluid encompasses all of these things.

As for the first question, I think it is referring to the human insulin being inserted into the DNA plasmid, though the question is very unclear. In that case, it would be gene splicing because the DNA plasmid and human insulin gene is cut up and these fragments are spliced together. But yeah, question is dodgy

[shivaji]

In the biological sense, what does inbreeding mean?

[Reus]

not quite sure but i'll take a stab at it:

possibly because the ETC is not working, the cell will require only on glycolysis for ATP. Hence, it will undergo glycolysis more to produce more energy, so more heat will be produced.

A question of my own:
In which stage of cellular respiration is the heat released the most or released at all?

Well first we need to understand that cellular respiration is an exothermic redox reaction which releases heat. Only ~40 % of energy is used from glucose to make ATP. as ~60% is lost as heat.
Hence ETC, as it produces the highest amount of ATP (32-34 ATP) in the entire reaction. 

[howlingwisdom]

Currently human insulin used by diabetics is mainly produced by bacteria into which the gene for human insulin production has been inserted. Which of the following terms identifies the insertion process?

A. Gene splicing
B. Mutation
C. Crossing over
D. Transformation.

The chose D. The correct answer is A.

Can someone please explain to me how this is not an example of transformation?

The actual process of gene insertion is also known as gene splicing

[katiesaliba]

Can someone confirm that the advantages of using mitochondrial DNA over nuclear DNA for determining the evolutionary relationships are:
- No recombination/crossing over like in nuclear DNA as it is only inherited from one parent (the mother)
- There is a high copy rate
- Mutates faster, hence it can be used in genetic comparisons between organisms which have diverged more recently
Are there any disadvantages of mtDNA or why one would  prefer the use of nuclear over mitochondrial DNA?

Note that only the non-coding regions mutate more rapidly. The coding region of mtDNA has a slow mutation rate.
Also, you can add that mtDNA is more abundant than nuclear DNA and is therefore more likely to be preserved and harnessed.

Nuclear DNA is more effective for separating direct relatives. Determines the phenotype (with environmental influence) for which natural selection works on.

[RazzMeTazz]

Does a sufficient  definition for the term 'hormone' need to include how they are involved in the regulation of body processes?

Would this be sufficient: chemical messenger secreted by endocrine glands directly into the bloodstream or interstitial fluid where they exert their effect on target cells in order to regulate body processes ?

Also what does it mean by "Stem cells are unique as they will replace themselves and relocate and replicate." ??
This was the answer to a question in a practice exam asking for two reasons why stem cells are unique (the other reason provided was, they can differentiate into many different cell types.)

Thanks

[AllG_]

Note that only the non-coding regions mutate more rapidly. The coding region of mtDNA has a slow mutation rate.
Also, you can add that mtDNA is more abundant than nuclear DNA and is therefore more likely to be preserved and harnessed.

Nuclear DNA is more effective for separating direct relatives. Determines the phenotype (with environmental influence) for which natural selection works on.

Thanks!

[katiesaliba]

Are my definitions okay for the following:

Genome- The full set of genes within a cell or individual.
Genotype- The range of alleles an organism possesses.

Also, how exactly do GMOs differ from TGOs. I know that GMOs include TGOs and that TGOs are 'organisms that carry in their genome one or more genes artificially introduced from another species', but what are some other examples of GMOs? Is gene therapy a technique that creates GMOs? What about gene regulation?

Thanks

[RazzMeTazz]

Does the term restriction fragment length polymorphism essentially just refer to variation in the length of restriction fragments produced ? :)

Thanks

[slothpomba]

The sympathetic nervous system controls:

A. Dilation of smooth muscles in arterioles
B. Slowing heart rate
C. Increasing peristalsis to aid digestion
D. Release of adrenalin

The correct answer is D.

Thanks!

Ive had these questions in uni physiology, i have no systematic way to go about it really, i've just done it through all memory brute force. The idea that sympathetic = fight and flight/turning things up and parasympathetic = rest and digest/turning things down fails as a method at a certain stage. Using these two principals, you could clearly knock about B and C with little biology knowledge however. I suppose it is the easiest way to go about it. Also imagine being really scared or having a large dose of caffeine, what would you feel? Imagine going for a fast run, what would need to happen in order to enable this?

One of the reasons its breaks down is vascular reasons. Some of the vasculature is actually relaxed and some is constricted. You want more blood pumping around under a fight/flight scenario (e.g. going for a run) but you don't want that blood pumped *everywhere*. It gets rather complicated too. Just be cautious about the whole fight/flight thing.

Also don't forget to thank everyone and up-vote answers :3 Everyone is a volunteer here and i see some people working very hard :3

[RazzMeTazz]

Ive had these questions in uni physiology, i have no systematic way to go about it really, i've just done it through all memory brute force. The idea that sympathetic = fight and flight/turning things up and parasympathetic = rest and digest/turning things down fails as a method at a certain stage. Using these two principals, you could clearly knock about B and C with little biology knowledge however. I suppose it is the easiest way to go about it. Also imagine being really scared or having a large dose of caffeine, what would you feel? Imagine going for a fast run, what would need to happen in order to enable this?

One of the reasons its breaks down is vascular reasons. Some of the vasculature is actually relaxed and some is constricted. You want more blood pumping around under a fight/flight scenario (e.g. going for a run) but you don't want that blood pumped *everywhere*. It gets rather complicated too. Just be cautious about the whole fight/flight thing.

Also don't forget to thank everyone and up-vote answers :3 Everyone is a volunteer here and i see some people working very hard :3

oh okay! Thanks so much for the explanation! It really helps.

Oh oops :S I seem to forget. Thanks for the reminder. Yes I'm really grateful to all the responses

[RazzMeTazz]

For all the different methods of radioisotope dating would this be sufficient (for the age of objects which can be dated by them)

1.) Carbon-14 : objects up to 60,000 years old
2.) Uranium-235: objects over 500,000 years old
3.) Potassium-40: objects over 500,000 years old
4) Rubidium-87: objects over 100 million years old

I seem to find different values (for how old objects can dated with these different methods ) in different sources... o.O

[ValiantIntellectual]

Is oxidative phosphorylation and the electron transport chain the same thing?

[flares]

I seem to find different values (for how old objects can dated with these different methods ) in different sources... o.O

same.... o.o

[vox nihili]

Is oxidative phosphorylation and the electron transport chain the same thing?

Yes and no. Just forget the term oxidative phosphorylation, you're not going to be asked about it.