How would you determine if there are multiple genes

You have read the literature about a lab that has isolated a gene for red pigmentation from petunias. The gene sequence is available in the database. You are a tomato geneticist and you want to study this gene in tomatoes. Describe the steps starting with the isolation of the gene and its complete characterization. i) How would you isolate the homologous gene for tomato? ii) How would you determine if there are multiple genes? iii) What kind of experiment would you do to determine the expression pattern of this gene? iv) How would you determine the extent of sequence similarity between the tomato gene and the petunia gene?