standard of answers in Success One (1 Viewer)

[IronyHigh]

Are the answers given in Success One for the extended response questions the best answers? I find that often they don't seem to have enough detail for the marks allocated... or is that just my tendency to waffle on? If I answered to the same depth that they do (which isn't very much) would I be able to get a band 6?

Here's one example (there are other examples):

Both the kiwi and the recently extinct moa of New Zealand are examples of flightless birds known as ratites. For many years comparative anatomy studies suggested that the two groups were quite closely related. Recently however, biochemical analysis of hte DNA suggest that they are not as clsoely related as first thought. Explain how biochemical analysis of hte moa and the kiwi can be used to show evolutionary relationship between them and other ratites.

Answer: The DNA of the moa, kiwi and other ratites can be compared using DNA sequencing. SIngle strands of DNA from two species can be mixed to form a hybrid molecule. the amount of pairing between the two strands is a measure of how similar hte two species are.


I should think we are supposed to include something about the number of differences between the species representing the steps in divergent evolution from a common ancestor? And I think the first sentence is unnecessary because that's what the question practically stated.

Also, are we supposed to know about the process of DNA-comparing? Before this i haven't even heard of the hybrid molecule....

 

[TheKing]

its called hybridisation of DNA
that is a molecule/enzyme/protein
is isolated and the DNA strip for the geen is split and they put the two serparated strands(for the different orangisms) together and measure the number of i'm pretty sure hydrogen bonds...
that establishes how closely related they are in the sense that the more bonds they have, the more common their version of the molecule.
there is a specific example i have somewhere, with stats but can't be bothered looking it up

and by the way i think the HSC sucess book is [pretty useless because u can find exemplar answers from real BOS site and in the front of the book they say that the answers may not be what the examiners are looking for or something along those lines...

 

[kimmeh]

IronyHigh, i think your right about the standard of answers in success one. theyre not detailed enough and sometimes dont correctly answer the question. our school uses sucess one for our topic tests but use a different marking criteria altogether but use their ideas as a starting ground what to write. i remember seeing a question with 3 marks allocated and the answers gave 2 sentences. dont rely on success one but use it as a starting point for your answers

 

[kow_dude]

Although it doesnt answer some questions in full, it does provide some information for syllabus dot points.

 

[IronyHigh]

Thanks for replying, guys. It makes more sense now. Heh, guess I had the expectation that text books should have the "right" answers.