grep, agrep, cut, sort and wc are very useful UNIX tools to get a quick overview of text files or extract certain information from files. Use these tools to answer the following questions:

1. Browse to the EBI website and download an EMBL formatted file of all nucleotide sequences from Rat-kangaroos (Potoroidae).
2. How many sequences are available? Did the download succeed? (Sometimes huge batch downloads break, so it is always a good idea to check if all sequences were retrieved!)
3. How many of the entries have the feature key 5'UTR?
4. How many and which tRNA-genes are annotated?
5. A very useful tool to convert files between different formats is readseq. Try the web version at http://www.ebi.ac.uk/cgi-bin/readseq.cgi to convert the formats and extract features.