lets all get pumped!

[akira88]

LOL Russ. All I know is that it's 25 pages long
Imagine if it were as long (in terms of content) as mid year!?

How do you know it's going to be 25 pages long?

[jasoN-]

http://www.vcaa.vic.edu.au/vcaa/vce/exams/examcovers/Oct_Nov_2010/2010biol2-cov.pdf

Materials supplied
• Question and answer book of 25 pages.
• Answer sheet for multiple-choice questions.

[bar0029]

you do Ito the B because this shows co-dominance

[golden]

you do Ito the B because this shows co-dominance

Really? Co-dominance occurs when the contributions of both alleles are visible in the phenotype. In the ABO example, the I^A and I^B alleles are co-dominant in producing the AB blood group phenotype, in which both A- and B-type antigens are made. (Wikipedia).

[thushan]

Incomplete dominance is not in the study design actually
And lucky it is, because it gets confusing
Example: HbA and HbS alleles for the gene controlling haemoglobin production

Consider the genotype HbA HbS.

phenotypes "production of haemoglobin A" and "production of haemoglobin S" are co-dominant
phenotypes "sickle-cell anaemia" and "no sickle-cell anaemia" are incompletely dominant

The same genotype can control more than one phenotype, which may have different dominance relationships (which is why we refer to PHENOTYPES not genotypes as being dominant or recessive).

[golden]

Incomplete dominance is not in the study design actually
And lucky it is, because it gets confusing
Example: HbA and HbS alleles for the gene controlling haemoglobin production

Consider the genotype HbA HbS.

phenotypes "production of haemoglobin A" and "production of haemoglobin S" are co-dominant
phenotypes "sickle-cell anaemia" and "no sickle-cell anaemia" are incompletely dominant

The same genotype can control more than one phenotype, which may have different dominance relationships (which is why we refer to PHENOTYPES not genotypes as being dominant or recessive).

It was on the 2006 VCAA paper question 10 multiple choice. But from the other answers you could deduce it had to be that one.

[Emile432]

Really? the phenotypes are dominant or recessive? isn't it the genotypes, because the trait will be expressed as the phenotype depending on which one is dominant??

[golden]

Incomplete dominance is not in the study design actually
And lucky it is, because it gets confusing
Example: HbA and HbS alleles for the gene controlling haemoglobin production

Consider the genotype HbA HbS.

phenotypes "production of haemoglobin A" and "production of haemoglobin S" are co-dominant
phenotypes "sickle-cell anaemia" and "no sickle-cell anaemia" are incompletely dominant

The same genotype can control more than one phenotype, which may have different dominance relationships (which is why we refer to PHENOTYPES not genotypes as being dominant or recessive).

Is that because the environment plays a role?

[masonnnn]

Incomplete dominance won't be used because it's really controversial over what is incomplete and what isn't.
ie. a usual example is a pink flower from a red and white flower -> used to be called incomplete dominance
but it's actually codominance as both red and white is expressed making it look pink to us.

[thushan]

That's the thing: it depends on the actual phenotype you are talking about. It's really a debatable topic - let's use that example about the white-red-pink flowers:

'production of white pigment' and 'production of red pigment' are co-dominant

BUT

'white flower' and 'red flower' are incompletely dominant

And yes, phenotypes NOT genotypes are dominant or recessive. Never use "dominant allele" - got that from Douchy

Douchy's awesome!

[Emile432]

Yer I love douchy too sooo... The trait is dominant or recessive, but not the actual phenotype itself? this is confusing me, since the phenotype is genotype + environment therefore a "phenotype" couldn't be recessive or dominant, could it?

[golden]

A phenotype can be dominant. Usually what distinguishes recessive from dominant is that dominant produces (more) proteins, making it dominant. Recessive phenotypes may not produce the protein.

A phenotype involves the biochemical, physiological and physical expression of the genotype. An expression (or not) of a protein therefore involves the phenotype.

[Emile432]

You may be right but..I am pretty sure that no matter what the environment throws at you, your genetically determined traits will not change or swap from one to the other. You get me?

[Russ]

Your environment can alter your genetic traits, it's the new big area of genetics research

e, it doesn't change the base sequence of your genome, but it can still have big effects

[slothpomba]

A read on wikipedia once that lemarcks theories are getting a little proof (but not exactly in the form he said them)