VCE Biology Question Thread

[cosine]

Thanks everyone. I didn't know what the word "saturated" meant in terms of a biology definition, but you all cleared that up, thanks.

Another question attached...why not c?

edit: thanks mr t-rav. also realised that another reason is because it's a linear chromosome, dammit..

Is the answer B?

[vox nihili]

Is the answer B?

It is indeed.

[paper-back]

Does adaptive radiation lead to speciaition?

[cosine]

Does adaptive radiation lead to speciaition?

I don't think this is always the case, but It could definitely be possible. If two populations experience different selection pressures from different environments, then overtime, they could diverse and evolve two different species.

[BakedDwarf]

Does adaptive radiation lead to speciaition?

I thought adaptive radiation is an outcome of speciation?

That is, after divergent evolution (speciation), species may spread out to occupy all available niches

[cosine]

Assistance with the attached images, please. All from 2006 exam 2

[vox nihili]

Assistance with the attached images, please. All from 2006 exam 2

What do you think first? Have a shot


In the exam if you don't know something, you wouldn't leave a blank space. Honing in your logic and "holy shit I don't know what to do here" skills is really important at this point of semester.

[cosine]

What do you think first? Have a shot


In the exam if you don't know something, you wouldn't leave a blank space. Honing in your logic and "holy shit I don't know what to do here" skills is really important at this point of semester.

The first three, honestly have no idea, seriously. The skull one, I chose W because it most closely resembles the human skull of Y but this was incorrect

[sunshine98]

Assistance with the attached images, please. All from 2006 exam 2

3
- first cross shows that marbled is dominant over clear
- 3rd cross also shows that marbled is dominant over spotted
- and then I puzzled over what was dominant spotted or clear and only way we can see this is form cross  2. The results of this cross suggest that either spotted or clear could be dominant over each other because if you try it out for either you get the same result. Here , one of the parents must be homozygote recessive and the other heterozygote for the two alleles
hence you can have
-3 genotypes from the homozygotes of each allele
- heterozygotes of the marbled allele with either spotted and clear (total of 5, so far )
- one with the clear and spotted (which either ways- if clear was dominant over spotted or vice versa - you would get one more genotype)
Total genotypes - 6 , thus answer is D
 4-
a- you cant conclude this , as I said above
b- no because if we have heterozygote of clear and marbled we would get marbled not clear
c- yes because its a classic cross and the answer says 2 of the 3 marbled are heterozygote
d- no because if they did you would have same outcome for both
I don't know the other q haven't learnt that evolution stuff properly
Hope this helps 
 

[BakedDwarf]

The first three, honestly have no idea, seriously. The skull one, I chose W because it most closely resembles the human skull of Y but this was incorrect

3) D. There are 3 alleles, let's say a, b and c. Do all the possible genotype combinations:
aa
ab
ac
bb
bc
cc
Therefore there are 6

4) C. When two heterozygotes are crossed, 2/3 of the offspring that show the dominant phenotype are heterozygous (just perform a cross if you are unsure)

D. If they are on the same chromosomes, there are two genotype possibilities for the offspring: SsWw or ssww because you are crossing SsWw x ssww, where the gametes produced on the heterozygous organism are SW and sw, and the gametes for the homozygous organism is sw (I would perform the test cross, but I don't know how to use latex). Therefore, there would be equal numbers of long, straight hair and short, wavy hair.

9) B. Just look at the teeth of that skull compared to the rest

[Biology24123]

Assistance with the attached images, please. All from 2006 exam 2

Q3: 6 different genotypes. Marbled/Marbles, Clear/clear, Spotted/spotted, Marbled/Clear, Marbled/spotted, Clear/spotted
Q4 The answer is C. If you do a punnet square for cross 3, 2/3 of the marbled offspring are heterozygous

[Biology24123]

3) D. There are 3 alleles, let's say a, b and c. Do all the possible genotype combinations:
aa
ab
ac
bb
bc
cc
Therefore there are 6

4) C. When two heterozygotes are crossed, 2/3 of the offspring that show the dominant phenotype are heterozygous (just perform a cross if you are unsure)

D. If they are on the same chromosomes, there are two genotype possibilities for the offspring: SsWw or ssww because you are crossing SsWw x ssww, where the gametes produced on the heterozygous organism are SW and sw, and the gametes for the homozygous organism is sw (I would perform the test cross, but I don't know how to use latex). Therefore, there would be equal numbers of long, straight hair and short, wavy hair.

9) B. Just look at the teeth of that skull compared to the rest

Pretty sure Q8 is D

[BakedDwarf]

Pretty sure Q8 is D

thats what it says (unless you read it before i modified it?)

[Biology24123]

thats what it says (unless you read it before i modified it?)

Yeah, you're explanation was right just chose the wrong option. All good!

[cosine]

I don't get how there can be three alleles for a certain gene. Does this mean that each individual just has two of these alleles? And could one allele be dominant to the other allele, but recessive to another one? So confusing