VCE Biology Question Thread

[cosine]

Are antibodies only effective towards viruses when they're not inside their host cell?

[Biology24123]

Are antibodies only effective towards viruses when they're not inside their host cell?

Yes

[tashhhaaa]

hey guys,

does anyone know where I could get Thushan's (or whoever did the Bio lecture's) notes from? (ie. the ones you buy)

[cosine]

How can I do this? Why is it not A?

[Biology24123]

How can I do this? Why is it not A?

Look at the data. A and C are the most related. Answer A has them as the most different. Answer is B

[cosine]

Look at the data. A and C are the most related. Answer A has them as the most different. Answer is B

Ah.. I read the most similarities. My bad..

[bananabreadbelle]

How can I do this? Why is it not A?

(I may not be correct, so feel free to educate me on this!)
But from the question I figured it is implied that the more differences in the Cytochrome-C amino acids between species, the longer/'more apart' two species have evolved from each other?

Between species A and species B, there are the MOST differences in amino acids (11) out of the three species - meaning they are the least related to each other out  of the three.

Whereas, between species A and species C, there are the LEAST differences in amino acids (3) - meaning they are the most related to each other out of the three (shorter time since they have evolved from each other).

Between species B and species C, there are 10 differences in amino acids, meaning they evolved from each other probably around the same time species A and species B evolved from each other.

Hence, I would say (B) is the correct answer? Mainly because the branch between species A and species C is relatively the 'shortest'. (Branch length represents the length of time two species have evolved from each other, longer branch = longer time // shorter branch = shorter time)

Hehe, don't know if that made sense, but hope that helped and I need to get stuck into revising this more as well, so thanks for the reminder.
 

[Biology24123]

(I may not be correct, so feel free to educate me on this!)
But from the question I figured it is implied that the more differences in the Cytochrome-C amino acids between species, the longer/'more apart' two species have evolved from each other?

Between species A and species B, there are the MOST differences in amino acids (11) out of the three species - meaning they are the least related to each other out  of the three.

Whereas, between species A and species C, there are the LEAST differences in amino acids (3) - meaning they are the most related to each other out of the three (shorter time since they have evolved from each other).

Between species B and species C, there are 10 differences in amino acids, meaning they evolved from each other probably around the same time species A and species B evolved from each other.

Hence, I would say (B) is the correct answer? Mainly because the branch between species A and species C is relatively the 'shortest'. (Branch length represents the length of time two species have evolved from each other, longer branch = longer time // shorter branch = shorter time)

Hehe, don't know if that made sense, but hope that helped and I need to get stuck into revising this more as well, so thanks for the reminder.
 

Makes perfect sense

[cosine]

How much do we need to know about gene cloning?

[vox nihili]

How much do we need to know about gene cloning?

You should be able to describe the process in some detail

[cosine]

You should be able to describe the process in some detail

Is PCR and transforming bacteria gene cloning? Because I know that gene cloning includes nuclear fusion and embryo splitting. Obviously PCR and recombinant plasmids are important, but is there anything we need to know about nuclear fusion and embryo splitting? Cheers.

[cosine]

Why is it that Meiosis does not occur when the chromosomes are not in homologous pairs?

[cosine]

"Index fossils can provide evidence of the relative age of fossils from different locations".

What does this mean? I know index fossils provide a date for the strata in which they are found in, but how can these fossils be used to provide evidence for the relative age of fossils from different locations?

[Sine]

"Index fossils can provide evidence of the relative age of fossils from different locations".

What does this mean? I know index fossils provide a date for the strata in which they are found in, but how can these fossils be used to provide evidence for the relative age of fossils from different locations?

So index fossils are found in different location and they have a known age. So if you were to find the same fossil(the index fossil) in two different geographical locations you could conclude that those strata have the same age. So if you knew the age of the index fossil you would be able to determine the ages of strata and thus the ages of fossils above and below it. This will allow you to be able to say that X(fossil) is more than Y years old or less the Z years old and by using multiple index fossils or other techniques you would be able to say it is between N years old and M years old.

Anyone doing Atar notes exampro practice exams yet?

[cosine]

So index fossils are found in different location and they have a known age. So if you were to find the same fossil(the index fossil) in two different geographical locations you could conclude that those strata have the same age. So if you knew the age of the index fossil you would be able to determine the ages of strata and thus the ages of fossils above and below it. This will allow you to be able to say that X(fossil) is more than Y years old or less the Z years old and by using multiple index fossils or other techniques you would be able to say it is between N years old and M years old.

Anyone doing Atar notes exampro practice exams yet?

Very well explained. I have the exampro but I haven't started it yet. Have you?

Also what is the main difference between gene flow and genetic drift? I know that gene flow involves the allele frequencies of a population sort of flowing, in a sense that new immigrants come in and attribute to the allele frequencies, and then emigrants leave a population and take with them the alleles, whereas genetic drift is the drifting of alleles in a population due to non-selective events.

Is gene flow constant? So the alleles are changing but the population remains constant, right? Like there is no significant drop in population size?