VCE Biology Question Thread

[heids]

Is it haploid?
Thanks for the explanations guys

No, diploid.  Reread our explanations!  Haploid = n, one set of chromosomes, diploid = 2n, 2 sets of chromosomes.  NORMALLY our body cells have 2 sets, remember one set from mum and one from dad?  Mitosis ends up with 46, so two sets of 23, so diploid.  Let me know if this doesn't make sense!

NB you can't ever change emoticon size

[StupidProdigy]

Do we need to know about crossing genotypes which have linked alleles (I don't understand the attachment)

[Sine]

Could I just verify a few things about the current study design! 
We are not required to know about : Result of change in blood pressure, factors effecting the opening and closing of the stomata, general water balance in humans.

Are we required to know about the specific functions of the various types of vacuoles?

[vox nihili]

Could I just verify a few things about the current study design! 
We are not required to know about : Result of change in blood pressure, factors effecting the opening and closing of the stomata, general water balance in humans.

Are we required to know about the specific functions of the various types of vacuoles?

Not required to know any of that.

[Sine]

Usually when people talk about VCE Biology they speak of the pedantic examiners & the importance of carefully wording answers. I feel examiners are not as harsh as people make them out to be; would you receive marks if you got the general idea of the answer down or is it that important to know exactly what the examiner wants. I've been doing practice exams for Unit 3(non-VCAA) and I'm not sure about marks gets you a marks and what doesn't. Any tips? Does it get less ambiguous with VCAA exams? As always thanks for the help!

[Jay.C]

Usually when people talk about VCE Biology they speak of the pedantic examiners & the importance of carefully wording answers. I feel examiners are not as harsh as people make them out to be; would you receive marks if you got the general idea of the answer down or is it that important to know exactly what the examiner wants. I've been doing practice exams for Unit 3(non-VCAA) and I'm not sure about marks gets you a marks and what doesn't. Any tips? Does it get less ambiguous with VCAA exams? As always thanks for the help!

Everything and anything that I have ever heard about VCAA biology examiners is that they are the harshest most pedantic creatures living on earth about the wording of answers. lol.    They may even steel your soul if you don't word an answer correctly.

[Jay.C]

Could someone please explain to me how to answer these two questions:

1. Why is the typical ratio for a dihybrid cross 9:3:3:1?
2. Why is the typical ratio for a monohybrid cross 1:2:1?

[heids]

Could someone please explain to me how to answer these two questions:

1. Why is the typical ratio for a dihybrid cross 9:3:3:1?
2. Why is the typical ratio for a monohybrid cross 1:2:1?

Punnett squares.

If you have two parents heterozygous at one locus, e.g. Aa and Aa, then they can each create two possible gametes.  In meiosis in the father, 2 of the resultant sperm will have the A allele and 2 will have the a allele.  So, an offspring has a 50% chance of being created from an A sperm, and 50% of being created from an a sperm.  Same with eggs.

So you make the square of possible genotypes (dad's gametes across the top, mum's down the side):

              A             a
A            AA            Aa
a            Aa            aa

Hence, of the offspring, 1 will have AA to every 2 with Aa to every 1 with aa.

Draw a Punnett square for an AaBb x AaBb cross, and you'll get the 9:3:3:1 ratio.  (When genes are on different chromosomes, that is).

[Biology24123]

Does anyone know VCAA's definition of rational drug design

[Jay.C]

Punnett squares.

If you have two parents heterozygous at one locus, e.g. Aa and Aa, then they can each create two possible gametes.  In meiosis in the father, 2 of the resultant sperm will have the A allele and 2 will have the a allele.  So, an offspring has a 50% chance of being created from an A sperm, and 50% of being created from an a sperm.  Same with eggs.

So you make the square of possible genotypes (dad's gametes across the top, mum's down the side):

              A             a
A            AA            Aa
a            Aa            aa

Hence, of the offspring, 1 will have AA to every 2 with Aa to every 1 with aa.

Draw a Punnett square for an AaBb x AaBb cross, and you'll get the 9:3:3:1 ratio.  (When genes are on different chromosomes, that is).

Hey thanks for the clarification, sorry I probably should have mentioned I know the mechanism behind it i just can't work out how to word It like if it were asked in an exam. Could you please answer them as if they were in an exam? sorry for the trouble!!

[Biology24123]

Hi guys

Just saw this question in a STAV exam. Do we need to know this?

[grannysmith]

Usually when people talk about VCE Biology they speak of the pedantic examiners & the importance of carefully wording answers. I feel examiners are not as harsh as people make them out to be; would you receive marks if you got the general idea of the answer down or is it that important to know exactly what the examiner wants. I've been doing practice exams for Unit 3(non-VCAA) and I'm not sure about marks gets you a marks and what doesn't. Any tips? Does it get less ambiguous with VCAA exams? As always thanks for the help!

Everything and anything that I have ever heard about VCAA biology examiners is that they are the harshest most pedantic creatures living on earth about the wording of answers. lol.    They may even steel your soul if you don't word an answer correctly.

Haha yeah, I know what you mean. Once you start doing past papers and studying the examiner's reports you get into the mindset that your answers should match theirs word for word. Of course, this is not the case. I'd have to agree with the importance of clear and succinct answers, however when people describe biology examiners as being 'pedantic' they're really just referring to the instances where specific words are required to obtain full marks. Funnily enough, the word 'specific' has been required in the past.

Another instance of VCAA being 'pedantic' (but I'd argue borderline unreasonable) was when you had to mention an 'intact' skin as opposed to just 'skin' as an example of a first-line of defence. Usually this only happens when the exam is on the easier side and so to compensate, they look for places where they can take off marks - this can make a difference at the top end, so you still want clear, succinct and accurate responses.

That being said, when VCAA puts forth a relatively ambiguous question which can be interpreted/answered in many different ways, they take this into account. It happened in last year's exam (2014). In fact, I'd say last year's exam had a decent amount of 'ambiguous' questions which as a result, necessitated a wider range of possible responses.

[cosine]

Everything and anything that I have ever heard about VCAA biology examiners is that they are the harshest most pedantic creatures living on earth about the wording of answers. lol.    They may even steel your soul if you don't word an answer correctly.

Lost a mark because when I was describing the response undertaken by plasma B cells, forgot to mention the specific production of anitbodies.

[vox nihili]

In other news, the new study design looks great   

[Berimbolo King]

Im pretty fucked i have a sac wednesday morning on Unit 4 Aos 1 and i know jack shit.
Teacher told us to know the proccess of PCR, purposes of gel electrophoresis, how DNA and the gel work together.
Also what is two independant assorting loci ?
If someone could explain all that for me thatd be super helpful.
 thanks in advance:)