Corn, Zucchini, and Avocado Pasta Salad

package (16 ounces) TriColor Rotini Pasta

small (heaping 2 cups) zucchini

corn

and 1/2 cups sliced tomatoes ((cherry, roma, or vine-ripened))

large avocado (chopped)

lemon juice

Salt and pepper

bottle (16 ounces) Zesty Italian Dressing (I use light)

Optional: parmesan cheese, fresh basil