One strand of a gene in Arabidopsis thaliana has the following nucleotide sequence:
atgagtgacgggaggaggaagaagagcgtgaacggaggtgcaccggcgcaaacaatcttggatgatcggagatctagtcttccggaagttgaagcttctccaccggctgggaaacgagctgttatcaagagtgccgatatgaaagatgatatgcaaaaggaagctatcgaaatcgccatctccgcgtttgagaagtacagtgtggagaaggatatagctgagaatataaagaaggagtttgacaagaaacatggtgctacttggcattgcattgttggtcgcaactttggttcttatgtaacgcatgagacaaaccatttcgtttacttctacctcgaccagaaagctgtgctgctcttcaagtcgggttaa

The function(s) of this gene is still uncertain.

(a) How might insertional mutagenesis be used to investigate the function(s) of the gene? 

(b) Design an experiment using RNA interference to probe the function(s) of the gene.