Which of these is not a challenge an organism encounters? a. reproducing b. staying healthy c. getting energy d. regenerating

Which of these is a major trend in land plant evolution? a) the trend toward smaller size b) the trend toward a gametophyte-dominated life cycle c) the trend toward a sporophyte-dominated life cycle d) the trend toward larger gametophytes

During an experiment, readings for blood pressure in a persons body were found to be constant . however , when he measured by a different blood pressure cuff , the readings differed by 15 points for each reading. this difference indicates that the results are

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.