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Author Topic: VCE Biology Question Thread  (Read 3571835 times)  Share 

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whys

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Re: VCE Biology Question Thread
« Reply #12540 on: June 02, 2020, 04:59:48 pm »
+2
The answer for this question is 'B' and not 'D' because, while both are Eukaryotic and animal cells do not have chloroplasts and plant cells do (another distinct feature). The most distinguishing, recognisable feature that separates a plant cell from an animal cell is the presence of a cell wall.

For Example:
Think of it like this, if you looked at two cells (plant and animal) without being able to see any organelles and just the outside, you could be able to distinguish between them, by checking if they have a cell wall or not.
I'm going to have to disagree with your explanation here. The answer isn't chloroplasts, yes, but not because you can't see the organelles (you actually will be able to see chloroplasts depending on the microscope you use). It's because chloroplasts are not present in all plant cells. For example, the cells on a plant's leaf have chloroplasts since they have access to the sun. But take the plant's roots into consideration - these root cells are still plant cells, but they don't have chloroplasts because that would be useless (they are under the ground and have no access to light energy). So, the reason why chloroplasts cannot be a distinguishing feature to tell between animal and plant cells is actually that not all plant cells have chloroplasts in the first place. However, all plant cells have cell walls, so this is the correct answer. In questions like these, choose the most correct alternative - although chloroplasts aren't exactly a 'wrong' answer, it's not the best answer in this case.
« Last Edit: June 02, 2020, 05:03:07 pm by whys »
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Re: VCE Biology Question Thread
« Reply #12541 on: June 02, 2020, 05:13:02 pm »
+1
Hello

Coat colour inheritance in certain cats is sex linked and codominant
Male cats can have yellow or black coat colours . Female cats may be yellow, black or tortoiseshell in colour. What would be the probability of having yellow female offspring if a tortoiseshell  female is crossed with a yellow male?
A 0%
B 25%
C 50%
D 75%

Why is the answer for this question B
Can’t work it out

Thank you
What attempts have you made with this question? It’s great to be given an answer however, you won’t really gain any skills of your own that way.

I will, however, give you a few hints:
1. Review what sex-linked inheritance and codominant mean.
2. What do those terms look like in a Punnett Square?
3. Check what offspring the question is asking for and what possibilities are available. Convert this to a percentage.

If a red flowered snap dragon is crossed with a white flowered one, the progeny will all be pink flowered. Which of the following is the most correct prediction of the ratios of offspring when a red snapdragon is crossed with a pink snapdragon ?
A 1 red:1pink
B. 1pink :3 white
C. 1red:2pink:1 white
D. 1 red: 1 pink: 2 white

Not sure how to do this question and why the answer is A. Also what does progeny mean

Thanks in advance
Here’s some clues:
1. A synonym for progeny is offspring.
2. Work out what alleles the pink snapdragon “parent” will have.
3. Use a Punnett square to find out what the offspring will look like.
4. Can your ratio be simplified? If so, try simplifying and see what you get. If not, pick the corresponding answer.
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s110820

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Re: VCE Biology Question Thread
« Reply #12542 on: June 02, 2020, 05:18:12 pm »
+1
I'm going to have to disagree with your explanation here. The answer isn't chloroplasts, yes, but not because you can't see the organelles (you actually will be able to see chloroplasts depending on the microscope you use). It's because chloroplasts are not present in all plant cells. For example, the cells on a plant's leaf have chloroplasts since they have access to the sun. But take the plant's roots into consideration - these root cells are still plant cells, but they don't have chloroplasts because that would be useless (they are under the ground and have no access to light energy). So, the reason why chloroplasts cannot be a distinguishing feature to tell between animal and plant cells is actually that not all plant cells have chloroplasts in the first place. However, all plant cells have cell walls, so this is the correct answer. In questions like these, choose the most correct alternative - although chloroplasts aren't exactly a 'wrong' answer, it's not the best answer in this case.

Hi, whys,

I definitely agree with your explanation! I was actually going to write a similar answer to yours but you beat me to it. But to add on to your point, I saw the option of "chloroplasts" more as a tangent rather than a tangible answer. For example, in any assessor's mind, the first characteristic that they know students would assume to be in a plant cell is the chloroplast as many students do in fact associate plant cells with chloroplasts because of its function to photosynthesise, which is pretty much the main characteristic of a plant.

However, I would just like to make it clear to any and every Biology student that assessors consistently try to throw "curveballs" at students or make students go on a bit of a tangent with information that is either a) irrelevant to the concept/question itself or what students commonly associate concepts of Biology with. The "chloroplast" question is a great example of this, so please be cautious of this by reading the question carefully and thinking in-depth about the options before making a final decision. Use the process of elimination to "knock out" the ridiculous or irrelevant answers and then, when you have your final two options, think about each concept carefully and ask yourself: does it make sense?

I would also recommend that when in exam situations, any and every Biology student should extend themselves by connecting the questions with the information that they have learnt and retained from their studies. For example, if you had this type of question in the exam, ask yourself: "Yes, chloroplasts are usually present in plant cells, would they be present in all plant cells?" and "if so, why or why not?" as well as "what other features usually distinguish one type of cell from another?" and "does this make sense?" in terms of the context given.

Hopefully, this helps :)

Have a great week and good luck with your assessment!

Kind regards,

Darcy Dillon.
QUT 2021 - Bachelor of Education (Primary).

Amelia257

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Re: VCE Biology Question Thread
« Reply #12543 on: June 02, 2020, 05:22:25 pm »
0
Would the red snapdragon be Pp

A bit confused with codominance

Also for this question
A section of DNA molecule is 30 base pairs long. What is the maximum number of amino acids this would code for?
A. 6 amino acids
B 15 amino acids
C 20 amino acids
D 10 amino acids

Why is the answer d and not b
Does one base pair code for one amino acid
Mod edit(PF): Merged double post :)
« Last Edit: June 05, 2020, 08:03:07 pm by PhoenixxFire »

GodNifty

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Re: VCE Biology Question Thread
« Reply #12544 on: June 02, 2020, 06:01:20 pm »
0
Also for this question
A section of DNA molecule is 30 base pairs long. What is the maximum number of amino acids this would code for?
A. 6 amino acids
B 15 amino acids
C 20 amino acids
D 10 amino acids

Why is the answer d and not b
Does one base pair code for one amino acid
How many codon bases code for an amino acid?
You then divide that by the amount of bases given in the DNA to get the amount of amino acids made

Amelia257

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Re: VCE Biology Question Thread
« Reply #12545 on: June 02, 2020, 06:15:47 pm »
0
1 codon codes for one amino acid??

AngelWings

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Re: VCE Biology Question Thread
« Reply #12546 on: June 02, 2020, 06:58:24 pm »
0
Would the red snapdragon be Pp

A bit confused with codominance
Ooh, almost got it, but not quite! Give it another try.

Codominant alleles mean that, if an organism has two different alleles, both are expressed (the phenotype is usually a blend, mix or a patchy version of the individual phenotypes expressed by each individual allele) and neither “masks” the other. A classic example of codominant alleles includes the ABO blood groups: you can have AB as your blood type and this means that you have both A and B alleles (A and B antigens on your cells). (It’s usually designated as IA IB for their genotype in a Punnett square.)

How many codon bases code for an amino acid?
You then divide that by the amount of bases given in the DNA to get the amount of amino acids made
I would probably slightly reword GodNifty’s clue to “How many nucleotide bases are in a codon?” and “How many amino acids does each codon correspond to?” (Sorry GodNifty! Hope that’s OK if I make a clarification.)
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Amelia257

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Re: VCE Biology Question Thread
« Reply #12547 on: June 02, 2020, 07:09:10 pm »
0
So  3 bases are in a codon and each codon corresponds to 1 amino acid?

For the snapdragon question it can only have 2 alleles right not 3?

Mod edit(PF): Merged posts :)
« Last Edit: June 05, 2020, 07:36:25 pm by PhoenixxFire »

AngelWings

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Re: VCE Biology Question Thread
« Reply #12548 on: June 02, 2020, 07:28:38 pm »
+1
So  3 bases are in a codon and each codon corresponds to 1 amino acid?
Correct! So, you know that 3 nucleotide bases are in 1 codon and 1 codon corresponds to 1 amino acid i.e. 3 nucleotide bases are involved in the production of 1 amino acid. From there, you can go back to GodNifty’s clue here:
You then divide that by the amount of bases given in the DNA to get the amount of amino acids made
... and hopefully that’ll give you a clue towards your original question:
Also for this question
A section of DNA molecule is 30 base pairs long. What is the maximum number of amino acids this would code for?
A. 6 amino acids
B 15 amino acids
C 20 amino acids
D 10 amino acids

Why is the answer d and not b
Does one base pair code for one amino acid

Does that help? The reason for the answer should be highlighted along the way by the concepts you used.
For the snapdragon question it can only have 2 alleles right not 3?
Yes, but also think about what colour a mix of red and white would make. Does this sound a bit familiar now? What alleles do you now think the red and pink snapdragon parents have? (This is alluded to in the first sentence of the question.)
« Last Edit: June 02, 2020, 07:34:51 pm by AngelWings »
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Amelia257

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Re: VCE Biology Question Thread
« Reply #12549 on: June 02, 2020, 07:37:42 pm »
+1
Would red be PP

And pink is Pp

AngelWings

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Re: VCE Biology Question Thread
« Reply #12550 on: June 02, 2020, 08:15:07 pm »
0
Would red be PP

And pink is Pp
Right on! :)
Have a go with the other clues I gave:
Here’s some clues:
1. A synonym for progeny is offspring.
2. Work out what alleles the pink snapdragon “parent” will have.
3. Use a Punnett square to find out what the offspring will look like.
4. Can your ratio be simplified? If so, try simplifying and see what you get. If not, pick the corresponding answer.
... and see how you go. You’ll see all the concepts join the dots along the way.
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Amelia257

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Re: VCE Biology Question Thread
« Reply #12551 on: June 02, 2020, 08:22:05 pm »
0
Does that mean white is pp

AngelWings

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Re: VCE Biology Question Thread
« Reply #12552 on: June 02, 2020, 08:43:01 pm »
0
Does that mean white is pp
Yes it is.
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Amelia257

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Re: VCE Biology Question Thread
« Reply #12553 on: June 02, 2020, 08:50:16 pm »
0
Ok. Thank you

Could you say the light dependent reaction takes place in the grana or would that be incorrect and do you have to say thylakoid membranes

Mod edit(PF):Merged posts :)
« Last Edit: June 05, 2020, 07:37:32 pm by PhoenixxFire »

whys

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Re: VCE Biology Question Thread
« Reply #12554 on: June 02, 2020, 09:13:48 pm »
+1
Could you say the light dependent reaction takes place in the grana or would that be incorrect and do you have to say thylakoid membranes
It is not incorrect. You can say the light-dependent stage occurs in the thylakoid membranes of the grana if you want to be specific, however I doubt they would mark you down if you just said 'grana'.
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