Arrange the steps in the correct order to explain how a muscle fiber contracts. myosin and actin protein filaments attach to each other. calcium ions release into the myofibrils. myosin filaments pull on the actin filaments. the nerve impulse reaches the neuromuscular junction. the motor neuron carries the nerve impulse. the sarcomere shortens. ↓ ↓ ↓ ↓ ↓

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.