A gene for skin pigmentation has two forms: the form (A) that produces the enzyme that makes melanin and a second form (a) that produces a defective enzyme that cannot mak
melanin. These two different forms of the gene for skin pigmentation are called

Even though the ostrich is a flightless bird, ostriches still possess wings that stretch approximately two meters across when fully extended. scientists speculate that when dinosaurs became extinct, some of the birds that lived during that time became land dwellers since they were able to consume the food that the dinosaurs once ate. over time, these species grew larger and heavier. eventually, the ostrich species became too big to fly. the wings found on ostriches are known as a. analogous structures. b. homologous structures. c. vestigial structures. d. symmetrical structures.