VCE Biology Question Thread

[FarAwaySS2]

Can somebody help me with this question?
- In certain trees, smooth bark is dominant over wrinkled.
a) If there are 100 offspring produced, how many will have wrinkled bark?

Don't genetic crosses give the chance of producing wrinkled bark, not the amount of offspring?

[grannysmith]

Can somebody help me with this question?
- In certain trees, smooth bark is dominant over wrinkled.
a) If there are 100 offspring produced, how many will have wrinkled bark?

Don't genetic crosses give the chance of producing wrinkled bark, not the amount of offspring?

That's impossible to answer without more background info.

That's correct.

[walkec]

I might seem like the biggest idiot asking this question, but how is co dominance different from incomplete dominance? Is co dominance that both traits are expressed equally in the heterozygote and incomplete dominance mean that both alleles are expressed equally, leading to a new phenotype (e.g. roan coloured cows?)

[dankfrank420]

I might seem like the biggest idiot asking this question, but how is co dominance different from incomplete dominance? Is co dominance that both traits are expressed equally in the heterozygote and incomplete dominance mean that both alleles are expressed equally, leading to a new phenotype (e.g. roan coloured cows?)

Nah man that's what this thread is for, don't feel bad for asking questions.

Co-dominance is when both alleles are expressed discretely - eg. a red and white spotted flower.
Incomplete dominance is when both alleles are mixed - eg. a pink flower is a mixture of red and white (and also roan coloured cows)

[grannysmith]

/Incomplete dominance is not required knowledge for the current study design, but I guess it's when you get a 'blend' or intermediate phenotype to that of the parental phenotypes. Roan cattle or pink snapdragons are typical examples.

Codominance is when both alleles are equally expressed in the phenotype (distinctively from each other) as they are equally dominant and independent. So like ABO blood types.

On the microscopic level however, I don't think there is much of a difference between the two (although perhaps there is a difference in terms of genetic interactions?).

Edit: beaten but oh well

[vox nihili]

/Incomplete dominance is not required knowledge for the current study design, but I guess it's when you get a 'blend' or intermediate phenotype to that of the parental phenotypes. Roan cattle or pink snapdragons are typical examples.

They took that off? Dodgy bastards 

[alondouek]

They took that off? Dodgy bastards 

Have they actually added anything new to the course since 2012? At this rate by 2020 VCE biology will consist of "this is an allele".

I was doing some catch-up tutoring for some people who moved into biology 3/4 a couple of weeks after the start of the school year, and it felt like every three or four subtopics I taught was prefaced with "apparently that isn't in the course anymore".

It's a shame because I felt that the pre-2013 course led in very well to units such as BIO1011 and BIO1022 (year 1 biology @ Monash) at university.

[Rishi97]

A polysaccharide that can be made in some animal cells is
a) Starch
b) Pectin
c) Glycogen
d) Cellulose

I know it cant be b or d but I cant decide between a and c
Thanks

[grannysmith]

Definitely c) Glycogen

[Sense]

Are you meant to simplify the genotype/phenotype ratio? Even if it doesn't ask for it simplified ?

[vox nihili]

A polysaccharide that can be made in some animal cells is
a) Starch
b) Pectin
c) Glycogen
d) Cellulose

I know it cant be b or d but I cant decide between a and c
Thanks

This is very much a google question.

Are you meant to simplify the genotype/phenotype ratio? Even if it doesn't ask for it simplified ?

They won't punish you for not simplifying it, because for some reason the VCE Biology course seems to assume that no one can do maths. So I wouldn't simplify to be honest.

[walkec]

Currently doing set review questions from Chapter 9 Nature of Biology in preparation for my SAC on Monday.

1c asks where would you locate a cell containing 20 unpaired chromosomes in a mouse. Would the answer be the in gonads of mice because this is where the gametes are produced. (I'm thinking if they're unpaired chromosomes then they haven't paired during fertilisation as of yet?)

[dankfrank420]

Yep, the haploid number of mice is 20 therefore all gametes would contain 20 chromosomes.

A terminology question here:

When we refer to the DNA code as degenerate, does it have the same meaning as saying it is redundant]? Ie. are the words interchangable?

[vox nihili]

Yep, the haploid number of mice is 20 therefore all gametes would contain 20 chromosomes.

A terminology question here:

When we refer to the DNA code as degenerate, does it have the same meaning as saying it is redundant]? Ie. are the words interchangable?

Either is better, though I'd go with degenerate probably. The best word for it is the technical term (though don't use it, not part of VCE Biol). Codon degeneracy is also known as the "wobble" (no shit) of the genetic code

[dankfrank420]

Ah cheers, sick profile pic by the way

Has anyone else started AoS2 (Evolution) yet?