VCE Biology Question Thread

[cosine]

Google them.  I'm happy to help, but your first step is to try out Wikipedia.  All the info is there, easily accessible.  Then ask when you get stuck and can't find something from that.

So I understand that fossilisation is the process in which the organic remains of dead organisms are preserved, and hence become fossilised, I also understand how index fossils can determine some time thing, like if a fossil is located on the lower strata, it is obviously much older than the fossils found on the top layers, but how does this serve as an 'index'?

As for the Eras, Epochs and periods, no idea at all

[heids]

So I understand that fossilisation is the process in which the organic remains of dead organisms are preserved, and hence become fossilised, I also understand how index fossils can determine some time thing, like if a fossil is located on the lower strata, it is obviously much older than the fossils found on the top layers, but how does this serve as an 'index'?

Fossilation = rapid burial remember.

Well, think about what it means if you get two of the same index fossil in two different areas; what can you tell about the rock layers in which they're buried?  (Index fossils are of species that only existed for a very short period of time... as far as we know, that is.)

Reading the Wikipedia article on index fossils was the thing that taught me index fossils, I HIGHLY recommend skimming the Wikipedia articles for basically all topics on the SD.  It will halve your questions.

As for the Eras, Epochs and periods, no idea at all

Literally just google 'geologic time scale' or 'eras epochs periods'.  It works wonders.

[cosine]

can someone explain the connection between Eras, Epochs and Periods? Cheers

[StupidProdigy]

can someone explain the connection between Eras, Epochs and Periods? Cheers

Literally just google 'geologic time scale' or 'eras epochs periods'.  It works wonders.

[cosine]

With immunology, why is it that the more precipitate produced, the more the similarities with between the species? Why would antibodies even be produced for proteins? So confusing

Could someone explain the difference between eras, epochs and periods for me, please?

Also, is there a difference between adaptive radiation and divergent evolution? I can't seem to differ between the two.

Cheers.

[heids]

With immunology, why is it that the more precipitate produced, the more the similarities with between the species? Why would antibodies even be produced for proteins? So confusing

Tb(embarrassingly)h I don't even know what you're talking about.

Could someone explain the difference between eras, epochs and periods for me, please?

Literally just google 'geologic time scale' or 'eras epochs periods'.  It works wonders.

... Don't you believe us!?!?
To prove it, I simply googled 'difference between era epoch period' and instantly got this and this and this and this.  All of which contain the answer in some shape or form, and there were many other possible sites to compare and ensure accuracy.  If you didn't find something with that search, there are other googles you could do.  In Uni you will have to find some things out yourself.  Get used to finding things that are only 10 seconds away, by yourself.  I'm not attacking you at all, it's just that by doing this you waste time - your own and others' - and don't learn basic valuable skills of searching out your own information.

If, having read at least 5 different sites, you still have a specific point of confusion, then ask, specifically.

Also, is there a difference between adaptive radiation and divergent evolution? I can't seem to differ between the two.

Same thing, I believe.

[cosine]

you waste time- your own and others'

You're right, but honestly if you're going to help me out, a disadvantaged kid attending a disadvantaged school comprised of teachers who lack enthusiasm, then I greatly appreciate it. No one is forcing you to 'waste' time to help me, but whenever you do, I am greatly thankful..

Apologies for asking questions, i can assure you this will be my last post on the biology thread. Farewell my fellow biologists, I honestly hope you have a successful ending with biology, gl

Cosine.

[BakedDwarf]

With immunology, why is it that the more precipitate produced, the more the similarities with between the species? Why would antibodies even be produced for proteins? So confusing

more precipitate formed ---> more antigen-antibody complexes -----> more similar protein since antibodies/antigens are complementary ----> hence, more similarities between species due to less protein differences and for mutations to accumulate
(not sure if this is what your question meant or if i answered it correctly)

I guess antibodies are produced to detect antigens? (antigens are any protein particles that bind to a specific component of the immune system and trigger an immune response)

[heids]

Cosine, I sincerely apologise if this caused offence. As you well know, I don't consider it wasting time to answer questions and help people out!  I'm not at all against asking questions.  I just know - from experience - that you can only deal with disadvantage by learning to search for the answers; the more disadvantaged your situation, the more Mr Google is your best friend!  It's simply a logical first step to try to answer your questions first, and then ask questions; when you've done that, we're only too happy to answer

cf. EulerFan's current sig.

[StupidProdigy]

So I've noticed a fair few sources have mtdna mutation rate mixed up. Just wanted to confirm if it is true the mtdna does mutate faster than normal dna? I did a prac exam question and it said it was slower...but I get a feeling it isn't

[BakedDwarf]

So I've noticed a fair few sources have mtdna mutation rate mixed up. Just wanted to confirm if it is true the mtdna does mutate faster than normal dna? I did a prac exam question and it said it was slower...but I get a feeling it isn't

I'm pretty sure it mutates much faster than normal DNA. Hence, why it's used to trace divergences of species over relatively short time.

Curious, what prac exam was this on?

[StupidProdigy]

I'm pretty sure it mutates much faster than normal DNA. Hence, why it's used to trace divergences of species over relatively short time.

Curious, what prac exam was this on?

Yeah I thought so! lisachem 2012

[StupidProdigy]

I thought the answer was a for this since the mosquito is just a vector..right or wrong haha? Thanks guys

[heids]

I thought the answer was a for this since the mosquito is just a vector..right or wrong haha? Thanks guys

Right.

[Sine]

Is this a sufficient explanation of DNA sequencing:

A DNA sample is mixed with primers, DNA polymerase, nucleotides and fluorescently marked dideoxynucleotides.
PCR is performed. When a fluorescently marked nucleotide is added this terminates polymerisation, subsequently this results in many fragments differing by a single nucleotide base.
Gel electrophoresis is performed on this sample separating these fragments by the number of base pairs, the end nucleotides are tagged with a fluorescent dye and are read as peaks on a chromatogram.

And a few questions;
Why is it DNA polymerase not Taq polymerase for Dna sequencing?

In PCR are the primers/nucleotides/Taq polymerase added after heating to 95C or before? I believe it is after but textbooks explain it as a mixture before heating. My thinking is that heating to 95C would denature Taq polymerase.