On a person’s hand, there can be 300,000-500,000 genetically distinct bacteria at one time. Wendy regularly puts hand sanitizer on because she is nervous about getting sick. The hand sanitizer kills 99% of these bacteria, but about 3,000-5,000 bacteria are left that are genetically resistant to the hand sanitizer.

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.