Using NCBI to filter results to retrieve one file for each of the several differ - (Oct/26/2013 )

Hi I'm a third year student who is doing Bioinformatics as a module at university. I'm enjoying it and want to continue it later. Anyway my question is:

I was given the following questions which I'm having trouble understanding:

I need to use the NCBI database to retrieve ONE file for each of the several forms of ferritin found in humans. Each file should contain the  complete mRNA sequence.

So I went to NCBI and did a search ' Human Ferritin' and put nucleotides tab on the right.

I got 5038 results

The second result said 'Human ferritin Heavy chain mRNA complete cds'

I clicked on the link to display 'related sequences'

Brought the results to 170

I saw things like gorilla in the results so I want to filter even more?

I can click the Homosapiens filter to get it down to 72? But do I want human or homosapiens because are they not the same thing?

The results has a mixture of human and homo etc but how can I just get it to display human?

And how can I filter the results to just display 'the complete mRNA sequence'

I have done some reading and one book says' you can limit the results by excluding 'EST' as these are partial sequences but on my tab I don't have that option I just have limit STS etc

The question says one of the  several types of ferritin found in humans. Several means ' More than two but not many' right? but I have so many results which I can't filter down even more.

I't cant be that many because we need to compile a table and compare the mRNA sequence elements after.

I don't want someone to do my work for be, I want to learn how to do it myself as I'm dyslexic and have trouble interpreting questions sometimes

luke

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